Kelly A Reynolds

Interests

Research

QMRAExposure scienceWater qualityFood safetyBuilt environmentTargeted hygieneEnvironmental microbiology

Teaching

Quantitative risk assessmentEnvironmental healthEnvironmentally acquired illnesses

Courses

Scholarly Contributions

Books

• Reynolds, K. A. (2019). Urban and Household Pollutio. New York, NY: Elsevier.
• Verhougstraete, M. P., Verhougstraete, M. P., Sexton, J. D., Sexton, J. D., Reynolds, K. A., & Reynolds, K. A. (2015). Recreational water contamination. Taylor and Francis Inc.. doi:10.4324/9781315693606

Chapters

• Artiola, J. F., Reynolds, K. A., & Brusseau, M. L. (2019). Urban and Household Pollution. In Environmental and Pollution Science. Third Edition. Academic Press. doi:10.1016/B978-0-12-814719-1.00018-5
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  Abstract The majority of people in the world live in cities and smaller urban areas. The high population densities and the infrastructure required to support these high populations generate unique environmental and human health issues. Managing urban development in a sustainable manner will be key to improving and maintaining human well-being while preserving environmental quality. This issue of sustainable urban development is one of the most critical issues of the 21st century. This chapter will present some of the major environment-related issues associated with urban areas.
• Reynolds, K. A. (2019). Validation of questionnaire methods to quantify recreational water ingestion. In Recreational Water Illnesses. Basel, Switzerland: MDPI.
• Verhougstraete, M. P., Sexton, J. D., & Reynolds, K. A. (2015). Recreational Water Exposure. In Handbook for Water and Health(pp 151-158). New York: EarthScan.
• Roane, T. M., Roane, T. M., Reynolds, K. A., Reynolds, K. A., Maier, R. M., Maier, R. M., Pepper, I. L., & Pepper, I. L. (2009). Chapter 2 – Microorganisms. In Environmental Microbiology. doi:10.1016/B978-0-12-370519-8.00002-X
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  Publisher Summary This chapter presents a discussion of the important microorganisms that are involved in environmental microbiology. The chapter presents a general description of their major structural features and functions that are related to the field of environmental microbiology. Analysis of 16S rRNA has led to the modern classification of living things into a three-domain system consisting of archaea, eucarya, and bacteria. The bacteria are the least structurally complex of the microorganisms with a single large circular chromosome located in the cytoplasm and without any compartmentalization of the cell, which offers the greatest metabolic flexibility. Archaea are somewhat similar to bacteria in size and shape, but they are genetically and biochemically quite different and may be the oldest form of life on Earth. Eukaryotes possess membrane-bound organelles in addition to a cytoplasmic membrane that is composed of a phospholipid bilayer with interspersed proteins for transport and degradation. Fungi, are a physically larger group of eucaryotic microorganisms and can be divided into three groups: molds, mushrooms, and yeasts. Fungi are extremely important in the degradation and recycling of dead plant, insect, and animal biomass. Protozoa are eukaryotic microorganisms that are important environmentally because they serve as the foundation of the food chain in many aquatic ecosystems. Algae are a group of single-celled or complex multi-cellular eucaryotic oxygenic photosynthetic microorganisms that sustain the food web in many aquatic environments. Viruses—prokaryotic or eukaryotic—are a group of biological entities that consist of a nucleic acid encapsulated within a protein coat and are obligate parasites of a range of bacteria and other living organisms. Viroids and prions are subviral particles that cause diseases in plants and animals respectively.
• Hurst, C. J., Reynolds, K. A., & Reynolds, K. A. (2007). Detection of viruses in environmental waters, sewage, and sewage sludges.. In .) Manual of Environmental Microbiology. Third Edition. American Society of Microbiology. doi:10.1128/9781555815882.CH23
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  This chapter describes techniques that can be used for concentrating human enteric viruses from environmental water, drinking water, raw wastewater, wastewater sludges, and wastewater effluents. The chapter presents the use of cartridge filter-based methods for concentrating viruses from environmental water, drinking water, and sewage effluent. The methods presented in this chapter for isolating viruses from raw sewage (raw wastewater) and wastewater sludges effectively utilize a process of directed adsorption and elution but differ in that they rely upon the wastewater solids to serve as an in situ adsorbent. A variety of sampling apparatuses may be needed when detecting viruses in environmental waters. The types of apparatus used for concentrating viruses from large volumes of environmental waters, drinking water, or sewage effluent by means of cartridge filtration are not standard equipment for most environmental microbiology laboratories. All of the cartridge filters described in the chapter can be presterilized within their holders by using ethylene oxide gas treatment before they are transported to the field. Objects less resistant to high heat, such as nonborosilicate glass and some polymer materials, can be surface sterilized by dousing or immersing them in commercial 95% ethanol and then igniting the alcohol with a flame. The infectivity of enteric viruses contained in environmental samples can be examined by inoculating the sample into cultures of either human or animal cells that are prepared in the laboratory as opposed to inoculating them into live animals.
• Hurst, C. J., Reynolds, K. A., & Reynolds, K. A. (2007). Sampling Viruses from Soil. In Manual of Environmental Microbiology. Third Edition. American Society of Microbiology. doi:10.1128/9781555815882.CH50
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  This chapter focuses on the methodology used to detect animal viruses in samples of soil. This methodology generally relies on elution and subsequent concentration of viruses from the soil, after which either cytopathogenicity or plaque formation assays are used to detect the viruses. These assays are based on the use of cultured animal cells as hosts for viral replication. The chapter also describes the use of plaque formation methodology to detect bacteriophages, viruses which infect bacteria. Other types of assay procedures, such as those based on the PCR, have also been developed to detect viruses in soil samples. Many different types of apparatus can be used to collect soil samples. These range from spoons and spatulas to shovels and powered augers. The available options for suitable sample containers include wide-mouthed screw-cap plastic jars and zipper closure plastic bags. Soil samples should be kept chilled to reduce thermal inactivation of the viruses. Bacteriophages can be detected by direct assay of soil suspensions using a plaque formation technique. If the presence of soil particles in the assay causes a problem, either because the resulting turbidity obscures assessment of the results or the number of contaminating soil bacteria and fungi carried along with the soil particles complicates plaque enumeration, then the bacteriophages can be eluted from the soil particles and the eluate can be assayed.
• Gerba, C. P., Reynolds, K. A., Dowd, S. E., & Pepper, I. L. (2001). Polymerase chain reaction from the detection of parasites and viruses. In Rapid Detection Assays for Food and Water. doi:10.1039/9781847551818-00049

Journals/Publications

• Ando, H., Murakami, M., Kitajima, M., & Reynolds, K. A. (2025). Wastewater-based estimation of temporal variation in shedding amount of influenza A virus and clinically identified cases using the PRESENS model. Environment international, 195, 109218.
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  Wastewater-based estimation of infectious disease prevalence in real-time assists public health authorities in developing effective responses to current outbreaks. However, wastewater-based estimation for IAV remains poorly demonstrated, partially because of a lack of knowledge about temporal variation in shedding amount of an IAV-infected person. In this study, we applied two mathematical models to previously collected wastewater and clinical data from four U.S. states during the 2022/2023 influenza season, dominated by the H3N2 subtype. First, we modeled the relationship between the detection probability of IAV in wastewater and FluA case counts, using a logistic function. The model revealed that a 50 % probability of IAV detection in wastewater corresponds to 0.53 (95 % CrI: 0.35-0.78) cases per 100,000 people, as observed in clinical surveillance over two weeks. Next, we applied the previously developed PRESENS model to IAV wastewater concentration data from California, revealing rapid and prolonged virus shedding patterns. The estimated shedding model was incorporated into an extended version of the PRESENS model to assess the variability in the relationship between IAV concentrations and case numbers across other states, including Massachusetts, New Jersey, and Utah. As a result, our analysis demonstrated the effectiveness of normalizing IAV concentrations with PMMoV (Pepper mild mottle virus) to accurately understand spatial distribution patterns of IAV prevalence. We successfully estimated FluA case counts from wastewater concentrations within a factor of two for 80 % of data from a state where 34 % of the state population was monitored by wastewater surveillance. Importantly, wastewater-based estimates provided real-time or leading insights (0-2 days) compared to clinical case detection in the three states, enabling early understanding of the incidence trends by limiting delays in data publication. These findings highlight the potential of wastewater surveillance to detect IAV outbreaks in near real-time and enhance efficiency of the infectious disease management.
• Heida, A., Maal-Bared, R., Veillette, M., Duchaine, C., Reynolds, K., Ashraf, A., Ogunseye, O., Jung, Y., Shulman, L., Ikner, L., Betancourt, W., Hamilton, K., & Wilson, A. (2025). Corrigendum to “Quantitative microbial risk assessment (QMRA) tool for modelling pathogen infection risk to wastewater treatment plant workers” [Water Research volume 260 (2024) 121858] (Water Research (2024) 260, (S0043135424007590), (10.1016/j.watres.2024.121858)). Water Research, 277. doi:10.1016/j.watres.2025.123258
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  The authors regret to report that some of the text in the Discussion inaccurately described the modelling case study results, which appear correctly in the figure and in the supplemental materials Table S3. Table S3 was also missing some of the results associated with these statements. Details on the errors and the corrected statements are given below and a full version of Table S3 with complete results. In, “For case (1) individual pathogens, G. duodenalis had the highest median gastrointestinal infection risk (5.4 × 10-2) and rotavirus had the lowest (5.2 × 10-4), above a 1 × 10-4 risk, a common comparison point used in QMRAs but originating from drinking water contexts for annual risks (Table S4),” “Table S4” should be replaced with “Table S3.” “L. pneumophila had the highest respiratory infection risk (5.8 × 10-2) (Table S4)” should read “Adenovirus had the highest median respiratory infection risk (6.6 × 10-3) (Table S3).” These values are available in a more comprehensive version of Table S3 at the end of this document. “G. duodenalis had the highest risk for both peak and non-peak hours for all pathogens considered in the ingestion risk scenario, and rotavirus had the lowest for peak and E. coli had the lowest for non-peak hours” should read “G. duodenalis had the highest median ingestion risk for peak hours, and C. hominis had the highest median ingestion risk for non-peak hours. Rotavirus had the lowest for peak and E. coli had the lowest for non-peak hours.” “The infection risk levels increased by 5-fold for all pathogens from non-peak to peak timing for the modeled scenarios, emphasizing that shift timing plays an important role in risk outcomes.” should read “The infection risk levels increased by up to 6 orders of magnitude for some pathogens, such as E. coli, from non-peak to peak timing for the modeled scenarios, emphasizing that shift timing plays an important role in risk outcomes.” Table S3. Summary statistics from simulation runs. (Now with more comprehensive results related to peak and non-peak inhalation risk estimates). [Table presented] Delignette-Muller and Dutang 2015 reference is for the sentence prior regarding the use of the fitdistrplus package. In Table 3, SARS-CoV-2 appears in the list of “pathogen of interest,” but this was not explored in the published work. For clarity, “…(4) respiratory infection risks for masks, N95 respirators, and no PPE.” should read “…(4) L. pneumophila respiratory infection risks for masks, N95 respirators, and no PPE.” For clarity, “Case (4) investigated the usage of cloth masks, surgical masks, and N95 respirators and their impact on the risk of respiratory infection from inhalation.” Should read “Case (4) investigated the usage of cloth masks, surgical masks, and N95 respirators and their impact on the risk of respiratory infection from L. pneumophila inhalation.” Figure 1 has a small pen mark next to the boxplot for Norovirus in the original manuscript. The figure below excludes this mark.[Figure presented] The authors would like to apologise for any inconvenience caused. Corresponding author: Amanda M. Wilson, PhD Assistant Professor, Environmental Health Sciences Mel and Enid Zuckerman College of Public Health University of Arizona
• Abney, S., Higham, C., Wilson, A., Ijaz, M., McKinney, J., Reynolds, K., & Gerba, C. (2024). Transmission of Viruses from Restroom Use: A Quantitative Microbial Risk Assessment. Food and Environmental Virology, 16(1). doi:10.1007/s12560-023-09580-1
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  Restroom use has been implicated in a number of viral outbreaks. In this study, we apply quantitative microbial risk assessment to quantify the risk of viral transmission by contaminated restroom fomites. We estimate risk from high-touch fomite surfaces (entrance/exit door, toilet seat) for three viruses of interest (SARS-CoV-2, adenovirus, norovirus) through eight exposure scenarios involving differing user behaviors, and the use of hand sanitizer following each scenario. We assessed the impacts of several sequences of fomite contacts in the restroom, reflecting the variability of human behavior, on infection risks for these viruses. Touching of the toilet seat was assumed to model adjustment of the seat (open vs. closed), a common touch point in single-user restrooms (home, small business, hospital). A Monte Carlo simulation was conducted for each exposure scenario (10,000 simulations each). Norovirus resulted in the highest probability of infection for all exposure scenarios with fomite surfaces. Post-restroom automatic-dispensing hand sanitizer use reduced the probability of infection for each virus by up to 99.75%. Handwashing within the restroom, an important risk-reduction intervention, was not found to be as effective as use of a non-touch hand sanitizer dispenser for reducing risk to near or below 1/1,000,000, a commonly used risk threshold for comparison.
• Ando, H., & Reynolds, K. (2024). Wastewater-based effective reproduction number and prediction under the absence of shedding information. Environment International, 194. doi:10.1016/j.envint.2024.109128
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  Estimating effective reproduction number (Re) and predicting disease incidences are essential to formulate effective strategies for disease control. Although recent studies developed models for inferring Re from wastewater-based data, they require information on shedding dynamics. Here, we proposed a framework of Re estimation and prediction without shedding information. The framework consists of a space-state model for smoothing wastewater-based data and a renewal equation modified for wastewater-based data. The applicability of the framework was tested with simulated data and real-world data on Influenza A virus (IAV) and SARS-CoV-2 concentration in wastewater in 2022/2023 season in the USA. We confirmed the state-space model effectively fits various simulated epidemic curves and real-world data. In simulations, we found wastewater-based Re (Reww) closely aligns with instantaneous clinical Re when shedding dynamics are rapid. For more prolonged shedding, Reww approximates a smoothed Re over time. We also observed the necessary sampling frequency to trace dynamics of wastewater concentration and Reww accurately in the framework varies depending on the precision of detection methods, the epidemic status, the transmissibility of infectious diseases, and shedding dynamics. By applying our framework to real-world data, we found Reww for SARS-CoV-2 showed similar trend and values to clinically-based Re. Reww for IAV ranged from 0.66 to 1.52 with a clear peak in the winter season, which agrees with previously reported Re. We also succeeded in predicting wastewater concentration in a few weeks from available wastewater-based data. These results indicate that our framework potentially enables near real-time monitoring of approximated Re and prediction of infectious disease dynamics through wastewater surveillance, which limits the delay between infection and reporting. Our framework is useful especially for regions where reliable clinical surveillance is not available and notifiable surveillance is abolished, and can be expanded to multiple infectious diseases that have been detected from wastewater.
• Heida, A., Maal-Bared, R., Veillette, M., Duchaine, C., Reynolds, K., Ashraf, A., Ogunseye, O., Jung, Y., Shulman, L., Ikner, L., Betancourt, W., Hamilton, K., & Wilson, A. (2024). Quantitative microbial risk assessment (QMRA) tool for modelling pathogen infection risk to wastewater treatment plant workers. Water Research, 260. doi:10.1016/j.watres.2024.121858
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  Wastewater treatment plants (WWTPs) provide vital services to the public by removing contaminants from wastewater prior to environmental discharge or reuse for beneficial purposes. WWTP workers occupationally exposed to wastewater can be at risk of respiratory or gastrointestinal diseases. The study objectives were to: (1) quantify pathogens and pathogen indicators in wastewater aerosols near different WWTP processes/unit operations, (2) develop a QMRA model for multi-pathogen and multi-exposure pathway risks, and (3) create a web-based application to perform and communicate risk calculations for wastewater workers. Case studies for seven different WWTP job tasks were performed investigating infection risk across nine different enteric and respiratory pathogens. It was observed that the ingestion risk among job tasks was highest for “walking the WWTP,” which involved exposure from splashing, bioaerosols, and hand-to-mouth contact from touching contaminated surfaces. There was also a notable difference in exposure risk during peak (5:00am-9:00am) and non-peak hours (9:00am- 5:00am), with risks during the peak flow hours of the early morning assumed to be 5 times greater than non-peak hours. N95 respirator usage reduced median respiratory risks by 77 %. The developed tool performs multiple QMRA calculations to estimate WWTP workers' infection risks from accidental ingestion or inhalation of wastewater from multiple pathogens and exposure scenarios, which can inform risk management strategies to protect occupational health. However, more data are needed to reduce uncertainty in model estimates, including comparative data for pathogen concentrations in wastewater during peak and non-peak hours. QMRA tools will increase accessibility of risk models for utilization in decision-making.
• Kulik, P., Alperin, M., Todd Barrett, K., Bekemeier, B., Documet, P., Francis, K., Gloria, C., Healy, E., Hileman, R., Kenefick, H., Lederer, A., Leider, J., McCormick, L., Prechter, L., Reynolds, K., Rogers, M., Rose, B., Scallan Walter, E., Walkner, L., , Zemmel, D., et al. (2024). The Need for Responsive Workforce Development during the Pandemic and Beyond: A Case Study of the Regional Public Health Training Centers. Journal of Public Health Management and Practice, 30(1). doi:10.1097/PHH.0000000000001835
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  Context: The COVID-19 pandemic underscored the importance of a strong public health infrastructure for protecting and supporting the health of communities. This includes ensuring an adaptive workforce capable of leading through rapidly changing circumstances, communicating effectively, and applying systems thinking to leverage cross-sector partnerships that help promote health equity. The 10 Regional Public Health Training Centers (PHTCs) advance the capacity of the current and future public health workforce through skill development and technical assistance in these and other strategic areas. Program: This study examines activities through which the Regional PHTCs and their partners supported the public health workforce during the pandemic. Representatives of the 10 Regional PHTCs completed a survey in the spring of 2022. The survey included (1) pulling trends in training usage from 2018-2021 annual performance reports and (2) questions assessing the type, content, and reach of training needs assessments, training and technical assistance, student placements, and PHTC Network collaborative activities that occurred from January 1, 2020, to December 31, 2021. Respondents also reflected on trends in use, challenges, lessons learned, stories of impact, and future PHTC practice. Evaluation: During the pandemic, the Regional PHTCs engaged in numerous efforts to assess needs, provide training and technical assistance to the practice community, facilitate projects that built student competency to support public health agency efforts, and collaborate as the PHTC Network on national-level initiatives. Across these activities, the Regional PHTCs adjusted their approaches and learned from each other in order to meet regional needs. Discussion: The Regional PHTCs provided student and professional development in foundational public health knowledge and skills within their regions and nationally while being flexible and responsive to the changing needs of the field during the pandemic. Our study highlights opportunities for collaboration and adaptive approaches to public health workforce development in a postpandemic environment.
• Sexton, J., Picton, J., Herdt, B., Black, E., & Reynolds, K. (2024). Removal, Kill, and Transfer of Bacteria from Hands by Antibacterial or Nonantibacterial Soaps After Handling Raw Poultry. Journal of Food Protection, 87(6). doi:10.1016/j.jfp.2024.100272
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  Hand hygiene is broadly recognized as a critical intervention in reducing the spread of disease-causing pathogens in both professional and personal uses. In this study, the impact of antibacterial (AB) or nonantibacterial soaps on the removal and postwash transfer of E. coli following the handling of raw poultry was assessed. Baseline bacterial contamination ranged between 107 and 109 CFU per hand. Hands were washed for 30 s in 40°C ± 2°C tap water using 2 mL of AB soap (0.5% and 1.0% Chloroxylenol, 0.5% Benzalkonium Chloride, or 4.0% Chlorhexidine Gluconate), non-AB soap (cosmetic/plain soap), or water. Postwash, water, and non-AB soap had a mean 3.63 and 3.65 Log10 reduction of E. coli on hands. AB treatments had a mean 4.19–4.35 Log10 reduction. Rinse water had mean bacterial counts of 8.62 and 8.88 Log10 CFU/mL for non-AB soap and water and 5.37–6.90 Log10 CFU/mL for AB treatments. Bacterial transfer was assessed by following the test subject's handling of a sterile polymer knife handle for 30 s postwash. E. coli transfer ranged from 263 to 903 CFU/handle for AB soaps and 1572 or 1709 CFU/handle for water and non-AB soap. Differences between AB and non-AB treatments were statistically significant (p < 0.0001) for hands and rinse water. Differences in transfer from hands to knife handle were not statistically significant (p = 0.139). Combined, these data highlight significant differences in the performance of AB soaps relative to non-AB soaps in a food handling environment-specific usage example and provide an unexplored assessment of the bactericidal vs. removal effects of AB vs. non-AB soaps on bacteria removed from the hands. These data reinforce the importance of hand hygiene, provide new details on the differences between AB vs. non-AB soaps, and highlight potential differences to inform food handling environment operators and public health personnel on how these products may impact food safety.
• Breshears, L. E., Mata-Robles, S., Tang, Y., Baker, J. C., Reynolds, K. A., & Yoon, J. Y. (2023). Rapid, sensitive detection of PFOA with smartphone-based flow rate analysis utilizing competitive molecular interactions during capillary action. Journal of hazardous materials, 446, 130699.
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  Perfluorinated-alkyl substances (PFAS) pose an unmet threat to the public because they are not strictly monitored and regulated. Perfluorinated-carbon alkyl chains (PFOA), a type of PFAS, at 70 fg/μL is the current health and safety recommendation. Current testing methods for PFOA and PFAS chemicals include HPLC-MS/MS and molecularly imprinted polymers, which are expensive, time-consuming, and require training. In this work, PFOA and PFOS detection was performed on a paper microfluidic chip using competitive interactions between PFOA/PFOS, cellulose fibers, and various reagents (L-lysine, casein, and albumin). Such interactions altered the surface tension at the wetting front and, subsequently, the capillary flow rate. A smartphone captured the videos of this capillary action. The samples flowed through the channel in less than 2 min. Albumin worked the best in detecting PFOA, followed by casein. The detection limit was 10 ag/μL in DI water and 1 fg/μL in effluent (processed) wastewater. Specificity to other non-fluorocarbon surfactants was also tested, using anionic sodium dodecyl sulfate (SDS), non-ionic Tween 20, and cationic cetrimonium bromide (CTAB). A combination of the reagents successfully distinguished PFOA from all three surfactants at 100% accuracy. This low-cost, handheld assay can be an accessible alternative for rapid in situ estimation of PFOA concentration.
• Jung, Y., Abney, S. E., Reynolds, K. A., Gerba, C. P., & Wilson, A. M. (2023). Evaluating infection risks and importance of hand hygiene during the household laundry process using a quantitative microbial risk assessment approach. American journal of infection control, 51(12), 1377-1383.
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  Contaminated laundry contributes to infectious disease spread in residential and home health care settings. The objectives were to (1) evaluate pathogen transmission risks for individuals doing laundry, and (2) compare hand hygiene timing to reduce risks.
• Lim, C. C., Yoon, J., Reynolds, K., Gerald, L. B., Ault, A. P., Heo, S., & Bell, M. L. (2023). Harmful algal bloom aerosols and human health. EBioMedicine, 93, 104604.
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  Harmful algal blooms (HABs) are increasing across many locations globally. Toxins from HABs can be incorporated into aerosols and transported inland, where subsequent exposure and inhalation can induce adverse health effects. However, the relationship between HAB aerosols and health outcomes remains unclear despite the potential for population-level exposures. In this review, we synthesized the current state of knowledge and identified evidence gaps in the relationship between HAB aerosols and human health. Aerosols from Karenia brevis, Ostreopsis sp., and cyanobacteria were linked with respiratory outcomes. However, most works did not directly measure aerosol or toxin concentrations and instead relied on proxy metrics of exposure, such as cell concentrations in nearby waterbodies. Furthermore, the number of studies with epidemiological designs was limited. Significant uncertainties remain regarding the health effects of other HAB species; threshold dose and the dose-response relationship; effects of concurrent exposures to mixtures of toxins and other aerosol sources, such as microplastics and metals; the impact of long-term exposures; and disparities in exposures and associated health effects across potentially vulnerable subpopulations. Additional studies employing multifaceted exposure assessment methods and leveraging large health databases could address such gaps and improve our understanding of the public health burden of HABs.
• Reynolds, K. A. (2023). Building water quality commissioning in healthcare settings: reducing Legionella and water contaminants utilizing a construction scheduling method. . Buildings, 13(10), 2553. doi:https://doi.org/10.3390/buildings13102533
• Reynolds, K. A. (2023). Managing building water disruptions in a post-COVID world: water quality and safety risk assessment tool for academic institutions and school settings . Buildings, 13(4), 921. doi:https://doi.org/10.3390/buildings13040921
• Reynolds, K. A., Yoon, J., Baker, J., Tang, Y., Mata-Robles, S., & Breshears, L. E. (2023). Rapid, sensitive detection of PFOA with smartphone-based flow rate analysis utilizing competitive molecular interactions during capillary action. Journal of Hazardous Materials. doi:10.1016/j.jhazmat.2022.130699
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  Perfluorinated-alkyl substances (PFAS) pose an unmet threat to the public because they are not strictly monitored and regulated. Perfluorinated-carbon alkyl chains (PFOA), a type of PFAS, at 70 fg/μL is the current health and safety recommendation. Current testing methods for PFOA and PFAS chemicals include HPLC-MS/MS and molecularly imprinted polymers, which are expensive, time-consuming, and require training. In this work, PFOA and PFOS detection was performed on a paper microfluidic chip using competitive interactions between PFOA/PFOS, cellulose fibers, and various reagents (L-lysine, casein, and albumin). Such interactions altered the surface tension at the wetting front and, subsequently, the capillary flow rate. A smartphone captured the videos of this capillary action. The samples flowed through the channel in less than 2 min. Albumin worked the best in detecting PFOA, followed by casein. The detection limit was 10 ag/μL in DI water and 1 fg/μL in effluent (processed) wastewater. Specificity to other non-fluorocarbon surfactants was also tested, using anionic sodium dodecyl sulfate (SDS), non-ionic Tween 20, and cationic cetrimonium bromide (CTAB). A combination of the reagents successfully distinguished PFOA from all three surfactants at 100% accuracy. This low-cost, handheld assay can be an accessible alternative for rapid in situ estimation of PFOA concentration.
• Wilson, A. M., Jung, Y., & Reynolds, K. A. (2023). Grappling with the Trade-offs of Cleaning and Disinfection: A Call for Targeted Hygiene. Environmental science & technology, 57(49), 20457-20459.
• Abney, S. E., Wilson, A. M., Ijaz, M. K., McKinney, J., Reynolds, K. A., & Gerba, C. P. (2022). Minding the matrix: The importance of inoculum suspensions on finger transfer efficiency of virus. Journal of applied microbiology, 133(5), 3083-3093.
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  The aim of this study was to determine how the transfer efficiency of MS-2 coliphage from the toilet seat to hands and fingertip to lip differs according to the suspension of the inoculum.
• Kerton, K. R., Wilson, A. M., Cabrera, N. L., Daniela, L., Reynolds, K. A., Joyce, L., & Beamer, P. (2022). Risk perceptions of drinking bottled vs. tap water in a low-income Latinx community in Nogales, Arizona. BMC Public Health.
• King, M. F., Wilson, A. M., Weir, M. H., López-García, M., Proctor, J., Hiwar, W., Khan, A., Fletcher, L. A., Sleigh, P. A., Clifton, I., Dancer, S. J., Wilcox, M., Reynolds, K. A., & Noakes, C. J. (2022). Modeling fomite-mediated SARS-CoV-2 exposure through personal protective equipment doffing in a hospital environment. Indoor air, 32(1), e12938.
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  Self-contamination during doffing of personal protective equipment (PPE) is a concern for healthcare workers (HCW) following SARS-CoV-2-positive patient care. Staff may subconsciously become contaminated through improper glove removal; so, quantifying this exposure is critical for safe working procedures. HCW surface contact sequences on a respiratory ward were modeled using a discrete-time Markov chain for: IV-drip care, blood pressure monitoring, and doctors' rounds. Accretion of viral RNA on gloves during care was modeled using a stochastic recurrence relation. In the simulation, the HCW then doffed PPE and contaminated themselves in a fraction of cases based on increasing caseload. A parametric study was conducted to analyze the effect of: (1a) increasing patient numbers on the ward, (1b) the proportion of COVID-19 cases, (2) the length of a shift, and (3) the probability of touching contaminated PPE. The driving factors for the exposure were surface contamination and the number of surface contacts. The results simulate generally low viral exposures in most of the scenarios considered including on 100% COVID-19 positive wards, although this is where the highest self-inoculated dose is likely to occur with median 0.0305 viruses (95% CI =0-0.6 viruses). Dose correlates highly with surface contamination showing that this can be a determining factor for the exposure. The infection risk resulting from the exposure is challenging to estimate, as it will be influenced by the factors such as virus variant and vaccination rates.
• Noakes, C. J., Reynolds, K. A., Wilcox, M., Dancer, S. J., Clifton, I., Sleigh, P. A., Fletcher, L. A., Khan, A., Hiwar, W., Proctor, J., Lopez-Garcia, M., Weir, M. H., Wilson, A. M., & King, M. (2021). Modeling fomite-mediated SARS-CoV-2 exposure through personal protective equipment doffing in a hospital environment. Indoor Air. doi:10.1111/ina.12938
• Reynolds, K. A. (2022). The impact of continuously active disinfectants (CADs). ISSA (International Sanitary Supply Association) Today.
• Reynolds, K. A., Cabrera, N. L., Wilson, A., Victory, K. R., Beamer, P. I., Larson, D., & Latura, J. (2022). Risk perceptions of drinking bottled vs. tap water in a low-income community on the US-Mexico Border. BMC Public Health. doi:10.21203/rs.3.rs-1451166/v1
• Reynolds, K. A., Hanlin, J., Myers, E., Gerba, C. P., Abney, S. E., Canter, K., & Wilson, A. M. (2022). An application for relating Legionella shower monitoring results to estimated health outcomes. Water Research.
• Reynolds, K. A., Verhougstraete, M. P., Mena, K. D., Sattar, S. A., Scott, E. A., & Gerba, C. P. (2022). Quantifying pathogen infection risks from household laundry practices. Journal of applied microbiology, 132(2), 1435-1448.
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  Contaminated laundry can spread infections. However, current directives for safe laundering are limited to healthcare settings and not reflective of domestic conditions. We aimed to use quantitative microbial risk assessment to evaluate household laundering practices (e.g., detergent selection, washing and drying temperatures, and sanitizer use) relative to log reductions in pathogens and infection risks during the clothes sorting, washer/dryer loading, folding and storing steps.
• Reynolds, K. A., Verhougstraete, M., & Gerba, C. P. (2022). Quantifying pathogen infection risks from household laundry practices. Journal of Applied Microbiology. doi:https://doi.org/10.1111/jam.15273
• Victory, K. R., Wilson, A. M., Cabrera, N. L., Larson, D., Reynolds, K. A., Latura, J., & Beamer, P. I. (2022). Risk perceptions of drinking bottled vs. tap water in a low-income community on the US-Mexico Border. BMC public health, 22(1), 1712.
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  Previous studies have shown that low-income Latinos generally drink bottled water over tap water and might be at increased risks for cavities from unfluoridated bottled water. In order to better design interventions, it is important to understand the risk perceptions of this unique high-risk yet historically marginalized group.
• Wilson, A. M., Canter, K., Abney, S. E., Gerba, C. P., Myers, E. R., Hanlin, J., & Reynolds, K. A. (2022). An application for relating Legionella shower water monitoring results to estimated health outcomes. Water research, 221, 118812.
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  Exposure models are useful tools for relating environmental monitoring data to expected health outcomes. The objective of this study was to (1) compare two Legionella shower exposure models, and (2) develop a risk calculator tool for relating environmental monitoring data to estimated Legionella infection risks and Legionnaires' Disease (LD) illness risks. Legionella infection risks for a single shower event were compared using two shower Legionella exposure models. These models varied in their description of partitioning of Legionella in aerosols and aerosol deposition in the lung, where Model 1 had larger and fewer aerosol ranges than Model 2. Model 2 described conventional vs. water efficient showers separately, while Model 1 described exposure for an unspecified shower type (did not describe it as conventional or water efficient). A Monte Carlo approach was used to account for variability and uncertainty in these aerosolization and deposition parameters, Legionella concentrations, and the dose-response parameter. Methods for relating infection risks to illness risks accounting for demographic differences were used to inform the risk calculator web application ("app"). Model 2 consistently estimated higher infection risks than Model 1 for the same Legionella concentration in water and estimated deposited doses with less variability. For a 7.8-min shower with a Legionella concentration of 0.1 CFU/mL, the average infection risks estimated using Model 2 were 4.8 × 10 (SD=3.0 × 10) (conventional shower) and 2.3 × 10 (SD=1.7 × 10) (water efficient). Average infection risk estimated by Model 1 was 1.1 × 10 (SD=9.7 × 10). Model 2 was used for app development due to more conservative risk estimates and less variability in estimated dose. While multiple Legionella shower models are available for quantitative microbial risk assessments (QMRAs), they may yield notably different infection risks for the same environmental microbial concentration. Model comparisons will inform decisions regarding their integration with risk assessment tools. The development of risk calculator tools for relating environmental microbiology data to infection risks will increase the impact of exposure models for informing water treatment decisions and achieving risk targets.
• Wilson, A. M., Victory, K. R., Reynolds, K. A., Cabrera, N. L., Larson, D., Latura, J., Burgess, J. L., & Beamer, P. (2022). Measured and modeled comparisons of chemical and microbial contaminants in tap, bottled and vended water in a U.S.-Mexico Border community. Environmental Science & Technology Water, 2(12), 2657-2667.
• Wilson, A. M., Victory, K. R., Reynolds, K. A., Cabrera, N. L., Larson, D., Latura, J., Burgess, J. L., & Beamer, P. (2022). Measured and modeled comparisons of chemical and microbial contaminants in tap, bottled and vended water in a U.S.-Mexico Border community. Environmental Science & Technology.
• Wilson, A. M., Victory, K. R., Reynolds, K. A., Cabrera, N. L., Larson, D., Latura, J., Sexton, J. D., Burgess, J. L., & Beamer, P. I. (2022). Measured and Modeled Comparisons of Chemical and Microbial Contaminants in Tap and Bottled Water in a US-Mexico Border Community. ACS ES&T water, 2(12), 2657-2667.
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  Tap water quality concerns and advertisements often drive increased bottled water consumption, especially in communities with historical tap water quality problems (e.g., Nogales, Arizona). The study objective was to assess contamination of municipal tap and bottled water in Nogales, Arizona. Bottled (sealed, open/partially consumed bottles, and reusable containers for vended water) and tap water samples were collected from 30 homes and analyzed for chemical and microbial contaminants. Fisher exact tests and Wilcoxon rank sum tests were used to compare proportions of positive samples and contaminant concentrations between tap and bottled water samples. While none of the chemical contaminants were above MCLs, there were statistically significantly greater concentrations and proportions of positive samples for some contaminants, including arsenic, in tap vs. bottled water. coli concentrations were >0 CFU/100mL in some unsealed bottled water samples but not for sealed bottles. This study demonstrates that 1) the measured concentrations in tap and bottled water likely pose low risks, as they are below the MCLs, 2) more education in this community on hygiene maintenance of refillable or opened bottled water containers is needed, and 3) using tap water over bottled water is advantageous due to likely lower risk and lower cost.
• Abrell, L. M., Reynolds, K. A., Jung, A. M., & Dennis, L. K. (2021). Stability of chemical UV filters in sunscreens exposed to vehicle cabin temperatures.. Am J Dermatol Research Reviews, 4(46). doi:10.28933/ajodrr-2021-06-0805
• Beamer, P. -., Plotkin, K. R., Gerba, C. P., Sifuentes, L. Y., Koenig, D. W., & Reynolds, K. A. (2014). Modeling of Human Viruses on Hands and Risk of Infection in an Office Workplace using Micro-Activity Data. Journal of Occupational and Environmental Hygiene, Advance Online Publication, DOI:10.1080/15459624.2014.974808.
• Chung, S., Breshears, L. E., Gonzales, A., Jennings, C. M., Morrison, C. M., Betancourt, W. Q., Reynolds, K. A., & Yoon, J. (2021). Norovirus Detection in Water Samples at the Level of Single Virus Copies per Microliter Using a Smartphone-based Fluorescence Microscope. Nature Protocols, 16, 1452-1475. doi:https://doi.org/10.1038/s41596-020-00460-7
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  Norovirus is a widespread public health threat and has a very low infectious dose. This protocol presents the extremely sensitive mobile detection of norovirus from water samples using a custom-built smartphone-based fluorescence microscope and a paper microfluidic chip. Antibody-conjugated fluorescent particles are immunoagglutinated and spread over the paper microfluidic chip by capillary action for individual counting using a smartphone-based fluorescence microscope. Smartphone images are analyzed using intensity- and size-based thresholding for the elimination of background noise and autofluorescence as well as for the isolation of immunoagglutinated particles. The resulting pixel counts of particles are correlated with the norovirus concentration of the tested sample. This protocol provides detailed guidelines for the construction and optimization of the smartphone- and paper-based assay. In addition, a 3D-printed enclosure is presented to incorporate all components in a dark environment. On-chip concentration and the assay of higher concentrations are presented to further broaden the assay range. This method is the first to be presented as a highly sensitive mobile platform for norovirus detection using low-cost materials. With all materials and reagents prepared, a single standard assay takes under 20 min. Although the method described is used for detection of norovirus, the same protocol could be adapted for detection of other pathogens by using different antibodies.
• Chung, S., Breshears, L. E., Gonzales, A., Jennings, C. M., Morrison, C. M., Betancourt, W. Q., Reynolds, K. A., & Yoon, J. Y. (2021). Norovirus detection in water samples at the level of single virus copies per microliter using a smartphone-based fluorescence microscope. Nature protocols, 16(3), 1452-1475.
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  Norovirus is a widespread public health threat and has a very low infectious dose. This protocol presents the extremely sensitive mobile detection of norovirus from water samples using a custom-built smartphone-based fluorescence microscope and a paper microfluidic chip. Antibody-conjugated fluorescent particles are immunoagglutinated and spread over the paper microfluidic chip by capillary action for individual counting using a smartphone-based fluorescence microscope. Smartphone images are analyzed using intensity- and size-based thresholding for the elimination of background noise and autofluorescence as well as for the isolation of immunoagglutinated particles. The resulting pixel counts of particles are correlated with the norovirus concentration of the tested sample. This protocol provides detailed guidelines for the construction and optimization of the smartphone- and paper-based assay. In addition, a 3D-printed enclosure is presented to incorporate all components in a dark environment. On-chip concentration and the assay of higher concentrations are presented to further broaden the assay range. This method is the first to be presented as a highly sensitive mobile platform for norovirus detection using low-cost materials. With all materials and reagents prepared, a single standard assay takes under 20 min. Although the method described is used for detection of norovirus, the same protocol could be adapted for detection of other pathogens by using different antibodies.
• Chung, S., Breshears, L. E., Morrison, C. M., Betancourt, W. Q., Reynolds, K. A., & Yoon, J. (2018). Smartphone-Based On-Chip Imaging of Microparticle Immunoagglutination towards Rapid and Near Single Particle Level Assay of Norovirus from Environmental Water Samples. Biosensors and Bioelectronics.
• Gerba, C. P., Reynolds, K. A., & Verhougstraete, M. (2018). Cost benefits of point-of-use devices to reduce waterborne diseases. Journal of Water and Health.
• Jung, A. M., Abrell, L. M., Reynolds, K. A., & Dennis, L. K. (2019). Determination of stability of chemical UV filters in commercial sunscreens exposed to summer temperatures. In Progress.
• Lopez, G. U., Kitajima, M., Reynolds, K. A., & Gerba, C. P. (2014). Comparison of Two Approaches in Determining Transfer Efficiency of Escherichia coli from Nonporous Fomites to Fingers. Applied and Environmental Microbiology.
• Reynolds, K. A. (2017). Con Vigencia Inmediata: Se Requiere que los Establecimientos de Cuidado de Salud Reduzcan los Riesgos de Contraer Legionellosis del Agua de la Llave [Effective Immediately: Healthcare Facilities Required to Reduce Tap]. Agua Latinoamérica.
• Reynolds, K. A. (2017). Controlando los Subproductos de la Desinfección en las Piscinas. [Controlling DBPs in Swimming Pools]. Agua Latinoamérica.
• Reynolds, K. A. (2021). - New Report on Waterborne Illness Highlights: Need for Public Protection. Water Conditioning and Purification International, 63(1).
• Reynolds, K. A. (2021). - Water Main Breaks and Public Health Risks. Water Conditioning and Purification International, 63(4).
• Reynolds, K. A. (2021). Drinking Water Advocacy Groups Critical of Consumer Right-to-Know Laws. Water Conditioning and Purification International, 63(3).
• Reynolds, K. A. (2021). Modelling the risk of SARS-CoV-2 infection associated with self-contamination through PPE doffing in a hospital environment. MedRxiv, 46.
• Reynolds, K. A. (2021). New Support for Monitoring and Reducing Contamination of Private Well Water Supplies. Water Conditioning and Purification International, 63(2).
• Reynolds, K. A. (2021). The impact of a continuously active disinfectant on bacterial surface concentrations and biofilm growth. InfectionControl.tips., 9.
• Reynolds, K. A. (2021). Tracking Hazardous Contaminant Exposures in Drinking Water- How Your Genes Can Tell the Story. Water Conditioning and Purification International, 63(5).
• Reynolds, K. A. (2021). – Nuevo Informe sobre las Enfermedades Transmitidas por el Agua Destaca la Necesidad de PGrupos de Defensa del Agua Potable Critican las Leyes sobre el Derecho a la Información del Consumidor. Agua Latinoamérica.
• Reynolds, K. A. (2021). – Protección de la Salud Pública. Agua Latinoamérica.
• Reynolds, K. A., & Valdez, M. K. (2014). Spread of infectious microbes during emergency medical response. American Journal of Infection Control.
• Reynolds, K. A., Abrell, L. M., & Dennis, L. K. (2021). Stability of chemical UV filters in sunscreens exposed to vehicle cabin temperatures. American Journal of Dermatological Research and Reviews, 4, 46.
• Reynolds, K. A., Sexton, J. D., Garavito, F., Anderson, B., & Ivaska, J. M. (2021). Impact of a Whole-Room Atomizing Disinfection System on Healthcare Surface Contamination, Pathogen Transfer, and Labor Efficiency. Critical care explorations, 3(2), e0340.
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  Healthcare surfaces contribute to nosocomial disease transmission. Studies show that despite standard guidelines and practices for cleaning and disinfection, secondary infection spread among healthcare workers and patients is common in ICUs. Manual terminal cleaning practices in healthcare are subject to highly variable results due to differences in training, compliance, and other inherent complexities. Standard cleaning practices combined with no-touch disinfecting technologies, however, may significantly lower nosocomial infection rates. The objective of this study was to evaluate the efficacy of a whole-room, no-touch disinfection intervention to reduce the concentration and cross-contamination of surface bacteria when used in tandem with manual cleaning protocols.
• Sexton, J. D., Sexton, J. D., Sexton, J. D., Reynolds, K. A., Norman, A., Reynolds, K. A., Norman, A., Mcclelland, D. J., & Mcclelland, D. J. (2021). Comparison of electric hand dryers and paper towels for hand hygiene: a critical review of the literature.. Journal of applied microbiology, 130(1), 25-39. doi:10.1111/jam.14796
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  Numerous studies are published on the benefits of electric hand dryers vs paper towels (PT) for drying hands after washing. Data are conflicting and lacking key variables needed to assess infection risks. We provide a rapid scoping review on hand-drying methods relative to hygiene and health risks. Controlled vocabulary terms and keywords were used to search PubMed (1946-2018) and Embase (1947-2018). Multiple researchers independently screened abstracts for relevance using predetermined criteria and created a quality assessment scoring system for relative study comparisons. Of 293 papers, 23 were included in the final analysis. Five studies did not compare multiple methods; however, 2 generally favoured electric dryers (ED); 7 preferred PT; and 9 had mixed or statistically insignificant results (among these, 3 contained scenarios favourable to ED, 4 had results supporting PT, and the remaining studies had broadly conflicting results). Results were mixed among and within studies and many lacked consistent design or statistical analysis. The breadth of data does not favour one method as being more hygienic. However, some authors extended generalizable recommendations without sufficient scientific evidence. The use of tools in quantitative microbial risk assessment is suggested to evaluate health exposure potentials and risks relative to hand-drying methods. We found no data to support any human health claims associated with hand-drying methods. Inconclusive and conflicting results represent data gaps preventing the advancement of hand-drying policy or practice recommendations.
• Suppes, L., Canales, R. A., Gerba, C. P., & Reynolds, K. A. (2014). Risk Assessment of Cryptosporidiosis among Recreational Swimmers in the United States. International Journal of Hygiene and Environmental Health.
• Wilson, A. M., King, M. F., López-García, M., Clifton, I. J., Proctor, J., Reynolds, K. A., & Noakes, C. J. (2021). Effects of patient room layout on viral accruement on healthcare professionals' hands. Indoor air, 31(5), 1657-1672.
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  Healthcare professionals (HCPs) are exposed to highly infectious viruses, such as norovirus, through multiple exposure routes. Understanding exposure mechanisms will inform exposure mitigation interventions. The study objective was to evaluate the influences of hospital patient room layout on differences in HCPs' predicted hand contamination from deposited norovirus particles. Computational fluid dynamic (CFD) simulations of a hospital patient room were investigated to find differences in spatial deposition patterns of bioaerosols for right-facing and left-facing bed layouts under different ventilation conditions. A microbial transfer model underpinned by observed mock care for three care types (intravenous therapy (IV) care, observational care, and doctors' rounds) was applied to estimate HCP hand contamination. Viral accruement was contrasted between room orientation, care type, and by assumptions about whether bioaerosol deposition was the same or variable by room orientation. Differences in sequences of surface contacts were observed for care type and room orientation. Simulated viral accruement differences between room types were influenced by mostly by differences in bioaerosol deposition and by behavior sequences when deposition patterns for the room orientations were similar. Differences between care types were likely driven by differences in hand-to-patient contact frequency, with doctors' rounds resulting in the greatest predicted viral accruement on hands.
• Wilson, A. M., King, M., Lopez-Garcia, M., Clifton, I. J., Proctor, J., Reynolds, K. A., & Noakes, C. J. (2021). Integrating CFD and exposure modeling for estimating viral exposures at the air-surface interface. AIAA, Session: Special Session: CFD and COVID-19. doi:10.2514/6.2021-2740
• Wilson, A. M., Reynolds, K. A., Proctor, J., Noakes, C. J., Lopez-garcia, M., King, M., & Clifton, I. J. (2021). Effects of patient room layout on viral accruement on healthcare professionals' hands.. Indoor air, 31(5), 1657-1672. doi:10.1111/ina.12834
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  Healthcare professionals (HCPs) are exposed to highly infectious viruses, such as norovirus, through multiple exposure routes. Understanding exposure mechanisms will inform exposure mitigation interventions. The study objective was to evaluate the influences of hospital patient room layout on differences in HCPs' predicted hand contamination from deposited norovirus particles. Computational fluid dynamic (CFD) simulations of a hospital patient room were investigated to find differences in spatial deposition patterns of bioaerosols for right-facing and left-facing bed layouts under different ventilation conditions. A microbial transfer model underpinned by observed mock care for three care types (intravenous therapy (IV) care, observational care, and doctors' rounds) was applied to estimate HCP hand contamination. Viral accruement was contrasted between room orientation, care type, and by assumptions about whether bioaerosol deposition was the same or variable by room orientation. Differences in sequences of surface contacts were observed for care type and room orientation. Simulated viral accruement differences between room types were influenced by mostly by differences in bioaerosol deposition and by behavior sequences when deposition patterns for the room orientations were similar. Differences between care types were likely driven by differences in hand-to-patient contact frequency, with doctors' rounds resulting in the greatest predicted viral accruement on hands.
• Wilson, A. M., Verhougstraete, M. P., Beamer, P. I., King, M. F., Reynolds, K. A., & Gerba, C. P. (2021). Frequency of hand-to-head, -mouth, -eyes, and -nose contacts for adults and children during eating and non-eating macro-activities. Journal of exposure science & environmental epidemiology, 31(1), 34-44.
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  Hand-to-face contacts are important for estimating chemical and microbial exposures. Few studies describe children's hand-to-eye or -nose contacts or adults' hand-to-face contacts. The study objective was to characterize hand-to-head (mouth, eyes, nose, and other) contacts for children in a daycare and adults in multiple locations. Macro-activities and sequences of hand-to-face contacts were recorded for 263 people observed for 30 min each. Statistically significant differences between locations, males and females, adults and children, and during eating and non-eating macro-activities were evaluated. Discrete Markov chains were fit to observed contact sequences and compared among adults and children during eating and non-eating macro-activities. No significant differences in contact frequency were observed between males and females with the exception of hand-to-nose contacts. Children tended to touch the mouth, eyes, and nose more frequently than adults during non-eating macro-activities. Significant differences in contact frequency were observed between locations. Transitional probabilities indicated that children make repetitive mouth, eye, and nose contacts while adults frequently transition to contacts of the head other than the mouth, eyes, or nose. More data are needed to evaluate the effect of age on adults' contact frequencies and to confirm lack of statistically significant differences between adults and children during eating macro-activities.
• Wilson, A. M., Verhougstraete, M. P., Donskey, C. J., & Reynolds, K. A. (2021). An agent-based modeling approach to estimate pathogen exposure risks from wheelchairs. American journal of infection control, 49(2), 206-214.
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  Contributions of contaminated wheelchairs to nosocomial pathogen transmission are relatively unknown. Our aim was to develop a model predicting pathogen exposures for patients utilizing wheelchairs and estimate exposure reduction potential of wheelchair disinfection between rides.
• Wilson, A. M., Verhougstraete, M. P., Reynolds, K. A., King, M., Gerba, C. P., & Beamer, P. I. (2021). Frequency of hand-to-head, -mouth, -eyes, and -nose contacts for adults and children during eating and non-eating macro-activities.. Journal of Exposure Science and Environmental Epidemiology, 31(1), 34-44. doi:10.1038/s41370-020-0249-8
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  Hand-to-face contacts are important for estimating chemical and microbial exposures. Few studies describe children’s hand-to-eye or -nose contacts or adults’ hand-to-face contacts. The study objective was to characterize hand-to-head (mouth, eyes, nose, and other) contacts for children in a daycare and adults in multiple locations. Macro-activities and sequences of hand-to-face contacts were recorded for 263 people observed for 30 min each. Statistically significant differences between locations, males and females, adults and children, and during eating and non-eating macro-activities were evaluated. Discrete Markov chains were fit to observed contact sequences and compared among adults and children during eating and non-eating macro-activities. No significant differences in contact frequency were observed between males and females with the exception of hand-to-nose contacts. Children tended to touch the mouth, eyes, and nose more frequently than adults during non-eating macro-activities. Significant differences in contact frequency were observed between locations. Transitional probabilities indicated that children make repetitive mouth, eye, and nose contacts while adults frequently transition to contacts of the head other than the mouth, eyes, or nose. More data are needed to evaluate the effect of age on adults’ contact frequencies and to confirm lack of statistically significant differences between adults and children during eating macro-activities.
• Wilson, A. M., Weir, M. H., Sexton, J. D., Reynolds, K. A., Noakes, C. J., Lerma, V. L., King, M., Jones, R. M., & Abney, S. E. (2021). Respirators, face masks, and their risk reductions via multiple transmission routes for first responders within an ambulance.. Journal of occupational and environmental hygiene, 18(7), 345-360. doi:10.1080/15459624.2021.1926468
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  First responders may have high SARS-CoV-2 infection risks due to working with potentially infected patients in enclosed spaces. The study objective was to estimate infection risks per transport for first responders and quantify how first responder use of N95 respirators and patient use of cloth masks can reduce these risks. A model was developed for two Scenarios: an ambulance transport with a patient actively emitting a virus in small aerosols that could lead to airborne transmission (Scenario 1) and a subsequent transport with the same respirator or mask use conditions, an uninfected patient; and remaining airborne SARS-CoV-2 and contaminated surfaces due to aerosol deposition from the previous transport (Scenario 2). A compartmental Monte Carlo simulation model was used to estimate the dispersion and deposition of SARS-CoV-2 and subsequent infection risks for first responders, accounting for variability and uncertainty in input parameters (i.e., transport duration, transfer efficiencies, SARS-CoV-2 emission rates from infected patients, etc.). Infection risk distributions and changes in concentration on hands and surfaces over time were estimated across sub-Scenarios of first responder respirator use and patient cloth mask use. For Scenario 1, predicted mean infection risks were reduced by 69%, 48%, and 85% from a baseline risk (no respirators or face masks used) of 2.9 × 10-2 ± 3.4 × 10-2 when simulated first responders wore respirators, the patient wore a cloth mask, and when first responders and the patient wore respirators or a cloth mask, respectively. For Scenario 2, infection risk reductions for these same Scenarios were 69%, 50%, and 85%, respectively (baseline risk of 7.2 × 10-3 ± 1.0 × 10-2). While aerosol transmission routes contributed more to viral dose in Scenario 1, our simulations demonstrate the ability of face masks worn by patients to additionally reduce surface transmission by reducing viral deposition on surfaces. Based on these simulations, we recommend the patient wear a face mask and first responders wear respirators, when possible, and disinfection should prioritize high use equipment.
• Wilson, A. M., Wilson, A. M., Weir, M. H., Weir, M. H., Scott, E. A., Scott, E. A., Reynolds, K. A., Reynolds, K. A., Bloomfield, S. F., & Bloomfield, S. F. (2021). Modeling COVID-19 infection risks for a single hand-to-fomite scenario and potential risk reductions offered by surface disinfection.. American journal of infection control, 49(6), 846-848. doi:10.1016/j.ajic.2020.11.013
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  We used a quantitative microbial risk assessment approach to relate log10 disinfection reductions of SARS-CoV-2 bioburden to COVID-19 infection risks. Under low viral bioburden, minimal log10 reductions may be needed to reduce infection risks for a single hand-to-fomite touch to levels lower than 1:1,000,000, as a risk comparison point. For higher viral bioburden conditions, log10 reductions of more than 2 may be needed to achieve median infection risks of less than 1:1,000,000.
• Wilson, A., Canales, R. A., Verhougstraete, M., & Reynolds, K. A. (2019). Validation of a Stochastic Discrete Event Model Predicting Virus Concentration on Nurse Hands. Risk Analysis.
• Yoon, J. Y., Reynolds, K. A., Morrison, C. M., Jennings, C. M., Gonzales, A., Chung, S., Breshears, L. E., & Betancourt, W. Q. (2021). Norovirus detection in water samples at the level of single virus copies per microliter using a smartphone-based fluorescence microscope.. Nature Protocols, 16(3), 1452-1475. doi:10.1038/s41596-020-00460-7
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  Norovirus is a widespread public health threat and has a very low infectious dose. This protocol presents the extremely sensitive mobile detection of norovirus from water samples using a custom-built smartphone-based fluorescence microscope and a paper microfluidic chip. Antibody-conjugated fluorescent particles are immunoagglutinated and spread over the paper microfluidic chip by capillary action for individual counting using a smartphone-based fluorescence microscope. Smartphone images are analyzed using intensity- and size-based thresholding for the elimination of background noise and autofluorescence as well as for the isolation of immunoagglutinated particles. The resulting pixel counts of particles are correlated with the norovirus concentration of the tested sample. This protocol provides detailed guidelines for the construction and optimization of the smartphone- and paper-based assay. In addition, a 3D-printed enclosure is presented to incorporate all components in a dark environment. On-chip concentration and the assay of higher concentrations are presented to further broaden the assay range. This method is the first to be presented as a highly sensitive mobile platform for norovirus detection using low-cost materials. With all materials and reagents prepared, a single standard assay takes under 20 min. Although the method described is used for detection of norovirus, the same protocol could be adapted for detection of other pathogens by using different antibodies.
• Contreras, R. D., Wilson, A. M., Garavito, F., Sexton, J. D., Reynolds, K. A., & Canales, R. A. (2020). Assessing virus infection probability in an office setting using stochastic simulation. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE, 17(1), 30-37.
• Malika, N. M., Barbagelatta, G., Penny, M., Reynolds, K. A., & Sinclair, R. (2020). Impact of Housing and Infrastructure on handwashing in Peru. International health.
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  The metropolitan area of Lima, Peru has a third of the nation's population living in slum dwellings that are hypothesized to contribute to inefficient household hygienic practices. The purpose of this study was to quantitatively assess which living conditions have the greatest impact on handwashing practices.
• Reynolds, K. A. (2020). - Wildfires and Water Quality. Water Conditioning and Purification International, 62(11).
• Reynolds, K. A. (2020). Ensuring Safe Building Water Supplies Before Reopening. Water Conditioning and Purification International, 62(6).
• Reynolds, K. A. (2020). Experts Weigh in on Waterborne Coronavirus Transmission. Water Conditioning and Purification International, 62(4).
• Reynolds, K. A. (2020). Infectious Diseases Can Spread Via Drinking Water. Water Conditioning and Purification International, 62(3).
• Reynolds, K. A. (2020). La Preparación tiene que Mitigar los Brotes Inevitables de Enfermedades a Nivel Mundial. Agua Latinoamérica.
• Reynolds, K. A. (2020). Make-shift Pools and Essential POU Maintenance. Water Conditioning and Purification International, 62(8).
• Reynolds, K. A. (2020). Microbes and Emerging Chlorine Resistance. Water Conditioning and Purification International, 62(10).
• Reynolds, K. A. (2020). Preparedness Needs to Mitigate Inevitable Global Disease Outbreaks. Water Conditioning and Purification International, 62(1).
• Reynolds, K. A. (2020). Prevención de la Propagación de COVID-19 en el Lugar de Trabajo. Agua Latinoamérica.
• Reynolds, K. A. (2020). Preventing the Spread of COVID-19 in the Workplace. Water Conditioning and Purification International, 62(7).
• Reynolds, K. A. (2020). Private Well Water Arsenic Screening Validates the Need for POU/POE Water Treatment. Water Conditioning and Purification International, 62(2).
• Reynolds, K. A. (2020). Sanitary surveys: assessing risks to drinking water supplies. Water Conditioning and Purification International, 62(12).
• Reynolds, K. A. (2020). The Benefits and Risks of Bottled Water Supplies. Water Conditioning and Purification International, 62(9).
• Reynolds, K. A. (2020). – Incendios Forestales y Calidad del Agua. Agua Latinoamérica.
• Reynolds, K. A. (2020). – Los Beneficios y Riesgos de los Suministros de Agua Embotellada. Agua Latinoamérica.
• Reynolds, K. A., Malika, N. M., Barbagelatta, G., Penny, M., & Sinclair, R. (2020). Impact of Housing and Infrastructure on handwashing in Peru. International Health, 13(6), 615-623. doi:10.1093/inthealth/ihaa008
• Reynolds, K. A., Noakes, C. J., Proctor, J., Dancer, S., Sexton, J. D., Lopez-Garcia, M., Weir, M. H., King, M., Abney, S. E., & Wilson, A. M. (2020). COVID-19 and non-traditional mask use: How do various materials compare in reducing the infection risk for mask wearers?. Journal of Hospital Infection, 105, 640-642. doi:10.1016/j.jhin.2020.05.036
• Verhougstraete, M. P., Pogreba-Brown, K., Reynolds, K. A., Lamparelli, C. C., Zanoli Sato, M. I., Wade, T. J., & Eisenberg, J. N. (2020). A critical analysis of recreational water guidelines developed from temperate climate data and applied to the tropics. Water research, 170, 115294.
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  Recreational water epidemiology studies are rare in settings with minimal wastewater treatment where risk may be highest, and in tropical settings where warmer temperature influences the ecology of fecal indicator bacteria commonly used to monitor recreational waters. One exception is a 1999 study conducted in São Paulo Brazil. We compared the risk and exposure characteristics of these data with those conducted in the United Kingdom (UK) in the early 1990s that are the basis of the World Health Organization's (WHO) guidelines on recreational water risks. We then developed adjusted risk difference models (excess gastrointestinal illness per swimming event) for children (
• Verhougstraete, M. P., Wilson, A. M., Verhougstraete, M. P., Reynolds, K. A., & Donskey, C. J. (2020). Estimating the Contribution of a Contaminated Wheelchair to Pathogen Spread With an Agent-Based Model. Infection Control and Hospital Epidemiology, 41. doi:10.1017/ice.2020.1150
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  Background: Wheelchairs can contribute to healthcare-associated infection transmission due to direct contact with patients and healthcare workers and due to wide spatial movement in facilities. Objective: We utilized location data of a wheelchair to inform an agent-based model for estimating the contribution of a single contaminated patient ride in a wheelchair to subsequent environmental contamination and to estimate the potential for wheelchair disinfection between patients to disrupt this spread. Methods: The destination and origin of wheelchairs were tracked in several facility locations: specialty care services, long-term care, radiology, acute care, common spaces, domiciliary, and outpatient clinics. An agent-based model was developed in which the probability of the wheelchair traveling directly from one location to another was informed by wheelchair origin and destination data. We assumed that the first patient’s hands were contaminated with methicillin-resistant Staphylococcus aureus (MRSA). For each patient trip, each simulated patient made contact with the wheelchair arm rests and a surface in the destination location. To evaluate potential exposures of uninfected patients, all patients riding in the wheelchair after the contaminated patient were assumed to be uncontaminated. In total, 50 patient rides were simulated. The concentration and number of contaminated surfaces in each hospital area were compared in addition to the average concentration of MRSA on patient hands over time. The intervention simulation involved a disinfection of wheelchair armrests with 90%, 70%, or 50% efficacy. Results: The 3 areas that had the largest estimated number of contaminated surfaces after 50 wheelchair trips following the first patient assumed to be infected were specialty care services, long-term care, and acute care. This finding was consistent with the paths that were most frequented by the wheelchair. Without cleaning between patients, the fiftieth patient to use the wheelchair had an average MRSA concentration of 41.5 CFU/cm2. With cleaning between patients, assuming a 50% cleaning efficacy, average MRSA concentration on the hands for the fiftieth patient was reduced to 7.4 ×10-14 CFU/cm2. Conclusions: We have demonstrated that cleaning, even with efficacies as low as 50%, may protect patients using contaminated wheelchairs from potential pathogen exposures. This study also demonstrates that tracking portable equipment can be useful not only for exposure modeling but also for predicting where the largest number of surfaces contaminated via portable equipment routes may be found. Future steps include performing a sensitivity analysis to evaluate the influence of spatial assumptions. Funding: None Disclosures: None
• Verhougstraete, M., Reynolds, K. A., Pearce-Walker, J., & Gerba, C. (2020). Cost-benefit analysis of point-of-use devices for health risks reduction from pathogens in drinking water. Journal of water and health, 18(6), 968-982.
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  Microbial contamination of drinking water post-municipal treatment is difficult to predict as a risk factor for human health. One method to reduce morbidity or mortality from unpredictable exposures is through point-of-use (POU) treatment devices. The goal of this project was to assess the cost-benefit of POU water treatment at the tap in terms of protection from microbes in drinking water. This project estimated: (1) incidence of acute illness (AI), sequela, and mortality associated with waterborne pathogens; (2) illness reduction rates from using POU devices; and (3) healthcare cost reductions associated with POU devices. Infection rates and costs associated with 10 of the most common waterborne pathogens were identified and used to calculate national annual costs. We estimated 9M AI, 0.6M sequela, and 1,400 mortality cases that occur annually in the USA from these pathogens. The greatest cost-benefit was seen when considering the totality of disease burden reduction (AI, sequela, and mortality) including all pathogens at a national level and applying a 35% infection reduction, resulting in a total cost per averted disease case of $1,815. This study suggests that it is cost-beneficial to prevent water-related illness using POU devices.
• Wilson, A. M., Abney, S. E., King, M. F., Weir, M. H., López-García, M., Sexton, J. D., Dancer, S. J., Proctor, J., Noakes, C. J., & Reynolds, K. A. (2020). COVID-19 and use of non-traditional masks: how do various materials compare in reducing the risk of infection for mask wearers?. The Journal of hospital infection, 105(4), 640-642.
• Wilson, A. M., King, M. F., López-García, M., Weir, M. H., Sexton, J. D., Canales, R. A., Kostov, G. E., Julian, T. R., Noakes, C. J., & Reynolds, K. A. (2020). Evaluating a transfer gradient assumption in a fomite-mediated microbial transmission model using an experimental and Bayesian approach. Journal of the Royal Society, Interface, 17(167), 20200121.
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  Current microbial exposure models assume that microbial exchange follows a concentration gradient during hand-to-surface contacts. Our objectives were to evaluate this assumption using transfer efficiency experiments and to evaluate a model's ability to explain concentration changes using approximate Bayesian computation (ABC) on these experimental data. Experiments were conducted with two phages (MS2, X174) simultaneously to study bidirectional transfer. Concentrations on the fingertip and surface were quantified before and after fingertip-to-surface contacts. Prior distributions for surface and fingertip swabbing efficiencies and transfer efficiency were used to estimate concentrations on the fingertip and surface post contact. To inform posterior distributions, Euclidean distances were calculated for predicted detectable concentrations (log PFU cm) on the fingertip and surface post contact in comparison with experimental values. To demonstrate the usefulness of posterior distributions in calibrated model applications, posterior transfer efficiencies were used to estimate rotavirus infection risks for a fingertip-to-surface and subsequent fingertip-to-mouth contact. Experimental findings supported the transfer gradient assumption. Through ABC, the model explained concentration changes more consistently when concentrations on the fingertip and surface were similar. Future studies evaluating microbial transfer should consider accounting for differing fingertip-to-surface and surface-to-fingertip transfer efficiencies and extend this work for other microbial types.
• Wilson, A. M., Reynolds, K. A., Jaykus, L. A., Escudero-Abarca, B., & Gerba, C. P. (2020). Comparison of estimated norovirus infection risk reductions for a single fomite contact scenario with residual and nonresidual hand sanitizers. American journal of infection control, 48(5), 538-544.
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  The purpose of this study was to relate experimentally measured log human norovirus reductions for a nonresidual (60% ethanol) and a residual (quaternary ammonium-based) hand sanitizer to infection risk reductions.
• Wilson, A. M., Verhougstraete, M. P., Reynolds, K. A., & Donskey, C. J. (2020). Estimating the Contribution of a Contaminated Wheelchair to Pathogen Spread With an Agent-Based Model. Infection Control and Hospital Epidemiology, 41(S1), s474-s474. doi:10.1017/ice.2020.1150
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  Background: Wheelchairs can contribute to healthcare-associated infection transmission due to direct contact with patients and healthcare workers and due to wide spatial movement in facilities. Objective: We utilized location data of a wheelchair to inform an agent-based model for estimating the contribution of a single contaminated patient ride in a wheelchair to subsequent environmental contamination and to estimate the potential for wheelchair disinfection between patients to disrupt this spread. Methods: The destination and origin of wheelchairs were tracked in several facility locations: specialty care services, long-term care, radiology, acute care, common spaces, domiciliary, and outpatient clinics. An agent-based model was developed in which the probability of the wheelchair traveling directly from one location to another was informed by wheelchair origin and destination data. We assumed that the first patient’s hands were contaminated with methicillin-resistant Staphylococcus aureus (MRSA). For each patient trip, each simulated patient made contact with the wheelchair arm rests and a surface in the destination location. To evaluate potential exposures of uninfected patients, all patients riding in the wheelchair after the contaminated patient were assumed to be uncontaminated. In total, 50 patient rides were simulated. The concentration and number of contaminated surfaces in each hospital area were compared in addition to the average concentration of MRSA on patient hands over time. The intervention simulation involved a disinfection of wheelchair armrests with 90%, 70%, or 50% efficacy. Results: The 3 areas that had the largest estimated number of contaminated surfaces after 50 wheelchair trips following the first patient assumed to be infected were specialty care services, long-term care, and acute care. This finding was consistent with the paths that were most frequented by the wheelchair. Without cleaning between patients, the fiftieth patient to use the wheelchair had an average MRSA concentration of 41.5 CFU/cm2. With cleaning between patients, assuming a 50% cleaning efficacy, average MRSA concentration on the hands for the fiftieth patient was reduced to 7.4 ×10-14 CFU/cm2. Conclusions: We have demonstrated that cleaning, even with efficacies as low as 50%, may protect patients using contaminated wheelchairs from potential pathogen exposures. This study also demonstrates that tracking portable equipment can be useful not only for exposure modeling but also for predicting where the largest number of surfaces contaminated via portable equipment routes may be found. Future steps include performing a sensitivity analysis to evaluate the influence of spatial assumptions. Funding: None Disclosures: None
• Wilson, A. M., Weir, M. H., Bloomfield, S. F., Scott, E. A., & Reynolds, K. A. (2020). Modeling COVID-19 infection risks for a single hand-to-fomite scenario and potential risk reductions offered by surface disinfection. American journal of infection control.
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  We used a quantitative microbial risk assessment approach to relate log disinfection reductions of SARS-CoV-2 bioburden to COVID-19 infection risks. Under low viral bioburden, minimal log reductions may be needed to reduce infection risks for a single hand-to-fomite touch to levels lower than 1:1,000,000, as a risk comparison point. For higher viral bioburden conditions, log reductions of more than 2 may be needed to achieve median infection risks of less than 1:1,000,000.
• Wilson, A., Verhougstraete, M., Beamer, P., King, M. F., Reynolds, K. A., & Gerba, C. P. (2020). Frequency of hand-to-head, -mouth, -eyes, and -nose contacts for adults and children during eating and non-eating macro-activities. Journal of Exposure Science and Environmental Epidemiology, 31, 34-44, 31, 34-44.
• Canales, R. A., Reynolds, K. A., Wilson, A. M., Fankem, S., Weir, M. H., Rose, J. B., Abd-Elmaksoud, S., & Gerba, C. P. (2019). Modeling the role of fomites in a norovirus outbreak. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE, 16(1), 16-26.
• Canales, R. A., Wilson, A. M., Sinclair, R. G., Soto-Beltran, M., Pearce-Walker, J., Molina, M., Penny, M., & Reynolds, K. A. (2019). Microbial study of household hygiene conditions and associated Listeria monocytogenes infection risks for Peruvian women. TROPICAL MEDICINE & INTERNATIONAL HEALTH, 24(7), 899-921.
• Chung, S., Breshears, L. E., Perea, S., Morrison, C. M., Betancourt, W. Q., Reynolds, K. A., & Yoon, J. (2019). Smartphone-Based Paper Microfluidic Particulometry of Norovirus from Environmental Water Samples at the Single Copy Level. ACS OMEGA, 4(6), 11180-11188.
• Chung, S., Breshears, L. E., Perea, S., Morrison, C. M., Betancourt, W. Q., Reynolds, K. A., & Yoon, J. (2019). Smartphone-Based Paper Microfluidic Particulometry of Norovirus from Environmental Water Samples at the Single Copy Level. ACS Omega, 4(6), 11180-11188. doi:https://doi.org/10.1021/acsomega.9b00772
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  Human enteric viruses can be highly infectious and thus capable of causing disease upon ingestion of low doses ranging from 10^0 to 10^2 virions. Norovirus is a good example with a minimum infectious dose as low as a few tens of virions, that is, below femtogram scale. Norovirus detection from commonly implicated environmental matrices (water and food) involves complicated concentration of viruses and/or amplification of the norovirus genome, thus rendering detection approaches not feasible for field applications. In this work, norovirus detection was performed on a microfluidic paper analytic device without using any sample concentration or nucleic acid amplification steps by directly imaging and counting on-paper aggregation of antibody-conjugated, fluorescent submicron particles. An in-house developed smartphone-based fluorescence microscope and an image-processing algorithm isolated the particles aggregated by antibody–antigen binding, leading to an extremely low limit of norovirus detection, as low as 1 genome copy/μL in deionized water and 10 genome copies/μL in reclaimed wastewater.
• Gerba, C. P., Reynolds, K. A., & Verhougstraete, M. (2017). Lead in drinking water: Point of use cost benefit analysis.. Environmental Health Perspectives.
• Horne, Y. O., Tran, T., Reynolds, K. A., Parks, J., Beamer, P. I., & Abrell, L. (2019). Seasonal Variation of Water Quality in Unregulated Domestic Wells.. International journal of environmental research and public health, 16(9), 1569. doi:10.3390/ijerph16091569
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  In the United States (U.S.), up to 14% of the population depend on private wells as their primary drinking water source. The U.S. government does not regulate contaminants in private wells. The goals of this study were to investigate the quality of drinking water from unregulated private wells within one mile (1.6 kilometers) of an effluent-dominated river in the arid Southwest, determine differences in contaminant levels between wet and dry seasons, and identify contributions from human sources by specifically measuring man-made organic contaminants (perfluorooctanoic acid (PFOA), perfluorooctane sulfate (PFOS), and sucralose). Samples were collected during two dry seasons and two wet seasons over the course of two years and analyzed for microbial (Escherichia coli), inorganic (arsenic, cadmium, chromium, copper, lead, mercury, nitrate), and synthetic organic (PFOA, PFOS, and sucralose) contaminants. Arsenic, nitrate, and Escherichia coli concentrations exceeded their respective regulatory levels of 0.01 mg/L, 10 mg/L, and 1 colony forming unit (CFU)/100 mL, respectively. The measured concentrations of PFOA and PFOS exceeded the respective Public Health Advisory level. Arsenic, PFOA, PFOS, and sucralose were significantly higher during the dry seasons, whereas E. coli was higher during the wet seasons. While some contaminants were correlated (e.g., As and Hg ρ = 0.87; PFOA and PFOS ρ = 0.45), the lack of correlation between different contaminant types indicates that they may arise from different sources. Multi-faceted interventions are needed to reduce exposure to drinking water above health-based guidelines.
• Hunter, C. M., McMullen, S., Edens, C., Baddour, L. J., McKeever, J., Reynolds, K. A., & Taren, D. L. (2019). Preventing Legionnaires' Disease Through a New Learning Opportunity: A Training on Legionella Water Management Programs. JOURNAL OF ENVIRONMENTAL HEALTH, 82(3), 44-46.
• Kurgat, E. K., Sexton, J. D., Garavito, F., Reynolds, A., Contreras, R. D., Gerba, C. P., Leslie, R. A., Edmonds-Wilson, S. L., & Reynolds, K. A. (2019). Impact of a hygiene intervention on virus spread in an office building. INTERNATIONAL JOURNAL OF HYGIENE AND ENVIRONMENTAL HEALTH, 222(3), 479-485.
• Reynolds, K. A. (2019). . Estimating the effect of a hand hygiene compliance and surface cleaning timing on infection risk reductions with a mathematical modeling approach. American Journal of Infection Control. doi:10.1016/j.ajic.2019.09.010
• Van, H., Parks, J., Tran, T., Abrell, L., Reynolds, K. A., & Beamer, P. I. (2019). Seasonal Variation of Water Quality in Unregulated Domestic Wells. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH, 16(9).
• Verhougstraete, M. P., Gerald, J. K., Gerba, C. P., & Reynolds, K. A. (2019). Cost-benefit of point-of-use devices for lead reduction. ENVIRONMENTAL RESEARCH, 171, 260-265.
• Verhougstraete, M. P., Verhougstraete, M. P., Reynolds, K. A., Munoz-gutierrez, K. M., & Canales, R. A. (2019). Floor and environmental contamination during glove disposal.. The Journal of hospital infection, 101(3), 347-353. doi:10.1016/j.jhin.2018.10.015
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  Evidence suggests that doffing and possibly disposal of used personal protective equipment (PPE) can lead to environmental contamination..To ascertain the potential for site and floor contamination when medical gloves are inappropriately disposed..Fifteen healthcare workers (HCWs) disposed of gloves inoculated with bacteriophage and a chemical dye into a wastebasket, located 1.22 m away. Following each trial, designated sample areas were visually inspected with a blacklight for fluorescent dye stains and swabbed with a 3M Letheen Broth sponge to quantify the bacteriophage..The area closest to the participant (0.61 m from the HCWs. Although the farthest distances (1.22-1.52 m) resulted in 14% bacteriophage- and 4% fluorescent dye-positive occurrences, there was no significant difference (P = 0.069) between the tracers. The bacteriophage and chemical dye indicate highest environmental contamination nearest the HCWs and both tracers could be appropriate for PPE disposal training..HCWs use gloves every workday and potentially could contaminate surrounding surfaces and floors, during improper disposal practices. Therefore, proper disposal techniques are required to minimize pathogen transmission by establishing industry-wide policies, adequate training, and education to HCWs.
• Verhougstraete, M., Pogreba Brown, K. M., Canales, R. A., Reynolds, K. A., Conde Lamparellie, C., Zanoli Satof, M., Wade, T., & Eisenburg, J. (2019). Using Local Data in a Quantitative Microbial Risk Assessment in Sao Paulo, Brazil. Water Research. doi:https://doi.org/10.1016/j.watres.2019.115294
• Wilson, A. M., Reynolds, K. A., & Canales, R. A. (2019). Estimating the effect of hand hygiene compliance and surface cleaning timing on infection risk reductions with a mathematical modeling approach. AMERICAN JOURNAL OF INFECTION CONTROL, 47(12), 1453-1459.
• Wilson, A. M., Reynolds, K. A., Verhougstraete, M. P., & Canales, R. A. (2019). Validation of a Stochastic Discrete Event Model Predicting Virus Concentration on Nurse Hands. RISK ANALYSIS, 39(8), 1812-1824.
• Alshammari, M., Reynolds, K. A., Verhougstraete, M., & O'Rourke, M. K. (2018). Comparison of Perceived and Observed Hand Hygiene Compliance in Healthcare Workers in MERS-CoV Endemic Regions. HEALTHCARE, 6(4).
• Alshammari, M., Reynolds, K. A., Verhougstraete, M., & O'Rourke, M. K. (2018). Comparison of Perceived and Observed Hand Hygiene Compliance in Healthcare Workers in MERS-CoV Endemic Regions. Healthcare.
• Canales, R. A., Wilson, A. M., Pearce-Walker, J. I., Verhougstraete, M. P., & Reynolds, K. A. (2018). Methods for Handling Left-Censored Data in Quantitative Microbial Risk Assessment. APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 84(20).
• Klug, K. E., Reynolds, K. A., & Yoon, J. (2018). A Capillary Flow Dynamics-Based Sensing Modality for Direct Environmental Pathogen Monitoring. Chemistry - A European Journal, 24(23), 6025-6029. doi:10.1002/chem.201800085
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  Toward ultra‐simple and field‐ready biosensors, we demonstrate a novel assay transducer mechanism based on interfacial property changes and capillary flow dynamics in antibody‐conjugated submicron particle suspensions. Differential capillary flow is tunable, allowing pathogen quantification as a function of flow rate through a paper‐based microfluidic device. Flow models based on interfacial and rheological properties indicate a significant relationship between the flow rate and the interfacial effects caused by target‐particle aggregation. This mechanism is demonstrated for assays of Escherichia coli K12 in water samples and Zika virus (ZIKV) in blood serum. These assays achieved very low limits of detection compared with other demonstrated methods (1 log CFU/mL E. coli and 20 pg/mL ZIKV whole virus) with an operating time of 30 s, showing promise for environmental and health monitoring.
• Munoz-Gutierrez, K., Canales, R. A., Reynolds, K. A., & Verhougstraete, M. (2018). Floor and environmental contamination during glove disposal. Journal of Hospital Infections. doi:10.1016/J.JHIN.2018.10.015
• Reynolds, K. A. (2018). A Capillary Flow Dynamics-Based Sensing Modality for Direct Environmental Pathogen Monitoring.. Chemistry (Weinheim an der Bergstrasse, Germany).
• Reynolds, K. A. (2018). Evaluation of hospital-grade disinfectants on viral deposition on surfaces after toilet flushing.. American journal of infection control.
• Reynolds, K. A. (2018). Tracking and controlling soft surface contamination in health care settings.. American journal of infection control.
• Sexton, J. D., Wilson, A. M., Sassi, H. P., & Reynolds, K. A. (2017). Tracking and controlling soft surface contamination in health care settings. American journal of infection control, 46(1), 39-43.
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  Study objectives were to track the transfer of microbes on soft surfaces in health care environments and determine the efficiency of an Environmental Protection Agency (EPA)-registered soft surface sanitizer in the health care environment.
• Sexton, J. D., Wilson, A. M., Sexton, J. D., Reynolds, K. A., & Canales, R. A. (2018). Modeling Surface Disinfection Needs To Meet Microbial Risk Reduction Targets.. Applied and environmental microbiology, 84(18). doi:10.1128/aem.00709-18
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  Nosocomial viral infections are an important cause of health care-acquired infections where fomites have a role in transmission. Using stochastic modeling to quantify the effects of surface disinfection practices on nosocomial pathogen exposures and infection risk can inform cleaning practices. The purpose of this study was to predict the effect of surface disinfection on viral infection risks and to determine needed viral reductions to achieve risk targets. Rotavirus, rhinovirus, and influenza A virus infection risks for two cases were modeled. Case 1 utilized a single fomite contact approach, while case 2 assumed 6 h of contact activities. A 94.1% viral reduction on surfaces and hands was measured following a single cleaning round using an Environmental Protection Agency (EPA)-registered disinfectant in an urgent care facility. This value was used to model the effect of a surface disinfection intervention on infection risk. Risk reductions for other surface-cleaning efficacies were also simulated. Surface reductions required to achieve risk probability targets were estimated. Under case 1 conditions, a 94.1% reduction in virus surface concentration reduced infection risks by 94.1%. Under case 2 conditions, a 94.1% reduction on surfaces resulted in median viral infection risks being reduced by 92.96 to 94.1% and an influenza A virus infection risk below one in a million. Surface concentration in the equations was highly correlated with dose and infection risk outputs. For rotavirus and rhinovirus, a >99.99% viral surface reduction would be needed to achieve a one-in-a-million risk target. This study quantifies reductions of infection risk relative to surface disinfectant use and demonstrates that risk targets for low-infectious-dose organisms may be more challenging to achieve.IMPORTANCE It is known that the use of EPA-registered surface disinfectant sprays can reduce infection risk if used according to the manufacturer's instructions. However, there are currently no standards for health care environments related to contamination levels on surfaces. The significance of this research is in quantifying needed reductions to meet various risk targets using realistic viral concentrations on surfaces for health care environments. This research informs the design of cleaning protocols by demonstrating that multiple applications may be needed to reduce risk and by highlighting a need for more models exploring the relationship among microbial contamination of surfaces, patient and health care worker behaviors, and infection risks.
• Suppes, L. M., Ernst, K. C., Abrell, L., & Reynolds, K. A. (2018). Validation of Questionnaire Methods to Quantify Recreational Water Ingestion. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH, 15(11).
• Verhougstraete, M., Gerald, J. K., Gerba, C. P., & Reynolds, K. A. (2019). Cost-benefit of point-of-use devices for lead reduction. Environmental Research.
• Verhougstraete, M., Reynolds, K. A., Pearce-Walker, J., Sexton, J. D., Bright, K. R., & Lothrop, N. (2018). Optimal strategies for monitoring irrigation water quality. AGRICULTURAL WATER MANAGEMENT, 199, 86-92. doi:https://doi.org/10.1016/j.agwat.2017.12.018
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  The quality of irrigation water drawn from surface water sources varies greatly. This is particularly true for waters that are subject to intermittent contamination events such as runoff from rainfall or direct entry of livestock upstream of use. Such pollution in irrigation systems increases the risk of food crop contamination and require adoption of best monitoring practices. Therefore, this study aimed to define optimal strategies for monitoring irrigation water quality. Following the analysis of 1357 irrigation water samples for Escherichia coli, total coliforms, and physical and chemical parameters, the following key irrigation water collection approaches are suggested: 1) explore up to 950 m upstream to ensure no major contamination or outfalls exists; 2) collect samples before 12:00 p.m. local time; 3) collect samples at the surface of the water at any point across the canal where safe access is available; and 4) composite five samples and perform a single E. coli assay. These recommendations comprehensively consider the results as well as sampling costs, personnel effort, and current scientific knowledge of water quality characterization. These strategies will help to better characterize risks from microbial pathogen contamination in irrigation waters in the Southwest United States and aid in risk reduction practices for agricultural water use in regions with similar water quality, climate, and canal construction.
• Verhougstraete, M., Reynolds, K. A., Sexton, J. D., Bright, K., & Lothrop, N. Z. (2018). Optimal strategies for monitoring irrigation water quality and the development of guidelines for the irrigation of food crops in the Southwestern United States. Agricultural Water Management.
• Gerba, C. P., & Reynolds, K. A. (2017). Quantifying the impact of hygiene interventions. Household and Personal Care Products, 12, 12-14.
• Koenig, D., Tamimi, A., Reynolds, K. A., Gerba, C. P., Maxwell, S., & Sifuentes, L. Y. (2017). Use of ATP Readings to Predict a Successful Hygiene Intervention in the Workplace. Food and Environmental Virology, 9, 14-19.
• Reynolds, K. A. (2017). Assessment of Waterborne Leptosporosis Infections. Water Conditioning and Purification International, 59(11), 48-50.
• Reynolds, K. A. (2017). Búsquedas de Internet Ayudan a Seguir la Pista de las Enfermedades Transmitidas por el Agua. Agua Latinoamérica.
• Reynolds, K. A. (2017). Comparison of Fluoride Levels in Tap and Bottled Water and Reported Use of Fluoride Supplementation in a United States-Mexico Border Community.. Frontiers in public health.
• Reynolds, K. A. (2017). Controlling Disinfection Byproducts in Swimming Pools. Water Conditioning and Purification International, 59(8), 40-42.
• Reynolds, K. A. (2017). Decreased Sperm Counts Associated with Waterborne Contaminants in the Developed World. Water Conditioning and Purification International, 59(9), 52-54.
• Reynolds, K. A. (2017). Effective Immediately: Healthcare Facilities Required to Reduce Legionellosis Risks from Tap Water. Water Conditioning and Purification International, 59(7), 54-56.
• Reynolds, K. A. (2017). Filtración en el Punto de Uso: Algo Esencial para un Plan de Seguridad del Agua. Agua Latinoamérica.
• Reynolds, K. A. (2017). Filtros de Punto de Uso para el Hogar: Centinelas para el Monitoreo a Largo Plazo del Agua de la Llave. Agua Latinoamérica.
• Reynolds, K. A. (2017). Growing Global Acceptance of Potable Reuse Water. Water Conditioning and Purification International, 59(10), 44-46.
• Reynolds, K. A. (2017). Household POU Filters: Sentinels for Long-term Tap Water Quality Monitorin. Water Conditioning and Purification International, 59(3), 62-64.
• Reynolds, K. A. (2017). Internet Queries Help Track Waterborne Disease. Water Conditioning and Purification International, 59(5), 44-46.
• Reynolds, K. A. (2017). Lluvias de Verano Aumentan el Riesgo de Virus Humanos en el Agua Subterránea. Agua Latinoamérica.
• Reynolds, K. A. (2017). Multi-Normalization and Interpolation Protocol to Improve Norovirus Immunoagglutination Assay from Paper Microfluidics with Smartphone Detection.. SLAS technology.
• Reynolds, K. A. (2017). POU Filtration: A Water Safety Plan Essential. Water Conditioning and Purification International, 59(1), 3.
• Reynolds, K. A. (2017). Prevalent Pepper Virus: A Contamination Tracker. Water Conditioning and Purification International, 59(2), 56-58.
• Reynolds, K. A. (2017). Recent Increase in Documented US Waterborne Disease Outbreaks. Water Conditioning and Purification International, 59(12), 46-48.
• Reynolds, K. A. (2017). Recuentos Menores de Espermatozoides Asociados con Contaminantes Propagados a través del Agua en el Mundo Desarrollado. Agua Latinoamérica.
• Reynolds, K. A. (2017). Summer Rains Increase Risk of Human Viruses in Groundwater. Water Conditioning and Purification International, 59(6), 52-54.
• Reynolds, K. A. (2017). Uncertain Effects of PFOA and PFOS. Water Conditioning and Purification International, 59(4), 44-46.
• Reynolds, K. A. (2017). Use of ATP Readings to Predict a Successful Hygiene Intervention in the Workplace to Reduce the Spread of Viruses on Fomites.. Food and environmental virology.
• Reynolds, K. A. (2017). Virus Prevalente del Chile: Un Marcador de la Contaminación. Agua Latinoamérica.
• Sexton, J. D., Sexton, J. D., & Reynolds, K. A. (2017). Legionellosis Prevention and Response Training for Environmental Health Professionals. American Journal of Infection Control, 45(6), S60-S61. doi:10.1016/j.ajic.2017.04.096
• Sexton, J. D., Sexton, J. D., Reynolds, K. A., Leslie, R. A., Humphrey, K., & Gerba, C. P. (2017). Effects of Disinfection on the Spread of Virus in an Outpatient Clinic. American Journal of Infection Control, 45(6), S23. doi:10.1016/j.ajic.2017.04.255
• Sifuentes, L. Y., Fankem, S., Reynolds, K., Tamimi, A. H., Gerba, C. P., & Koenig, D. (2017). Use of ATP Readings to Predict a Successful Hygiene Intervention in the Workplace to Reduce the Spread of Viruses on Fomites. FOOD AND ENVIRONMENTAL VIROLOGY, 9(1), 14-19.
• Verhougstraete, M., Reynolds, K. A., Sexton, J. D., Bright, K., & Lothrop, N. Z. (2016). Optimal strategies for monitoring irrigation water quality and the development of guidelines for the irrigation of food crops in the Southwestern United States. Agricultural Water Management.
• Victory, K. R., Cabrera, N. L., Larson, D., Reynolds, K. A., Latura, J., Thomson, C. A., & Beamer, P. I. (2017). Comparison of Fluoride Levels in Tap and Bottled Water and Reported Use of Fluoride Supplementation in a United States-Mexico Border Community. Frontiers in public health, 5, 87.
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  Compared to the general United States (U.S.) population, Arizona counties along the U.S.-Mexico border have a higher prevalence of dental caries, which can be reduced with adequate fluoride exposure. Because of concern regarding local tap water quality, fluoride-free bottled water consumption is common in this region, raising concern that families are not receiving adequate fluoride to promote dental health.
• Yoon, J., Reynolds, K. A., Park, T. S., & Cho, S. (2017). Multi-Normalization and Interpolation Protocol to Improve Norovirus Immunoagglutination Assay from Paper Microfluidics with Smartphone Detection. SLAS Technology, 22(6), 609-615. doi:10.1177/2472630317724769
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  Norovirus (NoV) is one of the leading causes of acute gastroenteritis, affecting 685 million people per year around the world. The best preventive measure is to screen water for possible NoV contamination, not from infected humans, preferably using rapid and field-deployable diagnostic methods. While enzyme immunoassays (EIAs) can be used for such detection, the low infectious dose as well as the generally inferior sensitivity and low titer of available NoV antibodies render critical challenges in using EIAs toward NoV detection. In this work, we demonstrated smartphone-based Mie scatter detection of NoV with immunoagglutinated latex particles on paper microfluidic chips. Using only three different concentrations of anti-NoV-conjugated particles, we were able to construct a single standard curve that covered seven orders of magnitude of NoV antigen concentrations. Multiple normalization steps and interpolation procedures were developed to estimate the optimum amount of antibody-conjugated particles that matched to the target NoV concentration. A very low detection limit of 10 pg/mL was achieved without using any concentration or enrichment steps. This method can also be adapted for detection of any other virus pathogens whose antibodies possess low sensitivity and low antibody titer.
• Gerba, C. P., Koenig, D. W., Sifuentes, L. Y., Plotkin, K. R., Beamer, P. -., & Reynolds, K. A. (2014). The Healthy Workplace Project: Reduced Viral Exposure in an Office Setting. Archives of Environmental and Occupational Health.
• McCracken, K. E., Angus, S. V., Reynolds, K. A., & Yoon, J. (2016). Multimodal Imaging and Lighting Bias Correction for Improved uPAD-based Water Quality Monitoring via Smartphones. Scientific Reports, 6(27529). doi:10.1038/srep27529
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  Smartphone image-based sensing of microfluidic paper analytical devices (μPADs) offers low-cost and mobile evaluation of water quality. However, consistent quantification is a challenge due to variable environmental, paper, and lighting conditions, especially across large multi-target μPADs. Compensations must be made for variations between images to achieve reproducible results without a separate lighting enclosure. We thus developed a simple method using triple-reference point normalization and a fast-Fourier transform (FFT)-based pre-processing scheme to quantify consistent reflected light intensity signals under variable lighting and channel conditions. This technique was evaluated using various angles/heights of light source, imaging backgrounds, and type/quality of light source. Further testing evaluated its handle of absorbance, quenching, and relative scattering intensity measurements from assays detecting four water contaminants – Cr(VI), total chlorine, caffeine, and E. coli K12 – at similar wavelengths using the green channel of RGB images. Between assays, this algorithm reduced error from μPAD surface inconsistencies and cross-image lighting gradients. Although the algorithm could not completely remove the anomalies arising from point shadows within channels or some non-uniform background reflections, it still afforded order-of-magnitude quantification and stable assay specificity under these conditions, offering one route toward improving smartphone quantification of μPAD assays for in-field water quality monitoring.
• Reynolds, K. A. (2016). Cryptosporidium risk from swimming pool exposures.. International journal of hygiene and environmental health.
• Reynolds, K. A. (2016). Multimodal Imaging and Lighting Bias Correction for Improved μPAD-based Water Quality Monitoring via Smartphones.. Scientific reports.
• Reynolds, K. A. (2016). Quantitative risk modeling of healthcare acquired infections and interventions using baseline data and simple models. American Journal of Infection Control- Supplement, 44(S3-27).
• Reynolds, K. A. (2016). The Healthy Workplace Project: Reduced Viral Exposure in an Office Setting. Archives of Environmental and Occupational Health, 71(3), 157-162.
• Reynolds, K. A. (2016). Use of a portable air disinfecting system to remove seeded coliphage in hospital rooms.. American journal of infection control.
• Reynolds, K. A., Gerba, C. P., Canales, R. A., & Suppes, L. (2014). Risk Assessment of Cryptosporidiosis among Recreational Swimmers in the United States. International Journal of Hygiene and Environmental Health, 219, 915-919.
• Sexton, J. D., Tamimi, A. H., Sexton, J. D., Reynolds, K. A., Pivo, T., Leslie, R. A., & Gerba, C. P. (2016). The Dynamics of Microbe Spread via Hands and Fomites Throughout an Outpatient Clinic. Open Forum Infectious Diseases, 3(suppl_1). doi:10.1093/ofid/ofw172.139
• Sifuentes, L. Y., Fankem, S. L., Reynolds, K., Tamimi, A. H., Gerba, C. P., & Koenig, D. (2017). Use of ATP Readings to Predict a Successful Hygiene Intervention in the Workplace to Reduce the Spread of Viruses on Fomites. Food and environmental virology.
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  The purpose of this study was to validate the use of adenosine triphosphate (ATP) for evaluating hygiene intervention effectiveness in reducing viral dissemination in an office environment. The bacterial virus MS-2 was used to evaluate two scenarios, one where the hand of an individual was contaminated and another where a fomite was contaminated. MS-2 was selected as a model because its shape and size are similar to many human pathogenic viruses. Two separate experiments were conducted, one in which the entrance door push plate was inoculated and the other in which the hand of one selected employee was inoculated. In both scenarios, 54 selected surfaces in the office were tested to assess the dissemination of the virus within the office. Associated surface contamination was also measured employing an ATP meter. More than half of the tested hands and surfaces in the office were contaminated with MS-2 within 4 h. Next, an intervention was conducted, and each scenario was repeated. Half of the participating employees were provided hand sanitizer, facial tissues, and disinfecting wipes, and were instructed in their use. A significant (p 
• Suppes, L. M., Canales, R. A., Gerba, C. P., & Reynolds, K. A. (2016). Cryptosporidium risk from swimming pool exposures. International journal of hygiene and environmental health, 219(8), 915-919.
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  Infection risk estimates from swimming in treated recreational water venues are lacking and needed to prioritize public health interventions in swimming pools. Quantitative infection risk estimates among different age groups are needed to identify vulnerable populations. High risk populations can be targeted during public health interventions, like education campaigns and pool operation improvements.
• Suppes, L., Canales, R. A., Gerba, C. P., & Reynolds, K. A. (2014). Cryptosporidium risk from swimming pool exposures. International Journal of Hygiene and Environmental Health.
• Suppes, L., Canales, R. A., Gerba, C. P., & Reynolds, K. A. (2016). Cryptosporidium risk from swimming pool exposures. International Journal of Hygiene and Environmental Health.
• Verhougstraete, M., & Reynolds, K. (2016). Use of a portable air disinfecting system to remove seeded coliphage in hospital rooms. American journal of infection control, 44(6), 714-5.
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  Health care-associated infections are a major problem worldwide, and the airborne route is believed to be a contributory source of secondary health care-associated infections. This study examined the efficacy of a portable air disinfecting system to remove seeded coliphage virus from the air in hospitals rooms. Aerosolized coliphage concentrations were not statistically different between treatment and no treatment measurements. However, future research should focus on additional investigations in the patient rooms that incorporate fomite and air testing alongside portable air filtration devices.
• Beamer, P. -., Plotkin, K. R., Gerba, C. P., Sifuentes, L. Y., Koenig, D. W., & Reynolds, K. A. (2015). Modeling of Human Viruses on Hands and Risk of Infection in an Office Workplace using Micro-Activity Data. Journal of Occupational and Environmental Hygiene, 12(4), 266-275.
• Beamer, P. I., Plotkin, K. R., Gerba, C. P., Sifuentes, L. Y., Koenig, D. W., & Reynolds, K. A. (2015). Modeling of human viruses on hands and risk of infection in an office workplace using micro-activity data. Journal of occupational and environmental hygiene, 12(4), 266-75.
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  Although the number of illnesses resulting from indirect viral pathogen transmission could be substantial, it is difficult to estimate the relative risks because of the wide variation and uncertainty in human behavior, variable viral concentrations on fomites, and other exposure factors. The purpose of this study was to evaluate the micro-activity approach for assessment of microbial risk by adapting a mathematical model to estimate probability of viral infection from indirect transmission. To evaluate the model, measurements of phage loading on fomites and hands collected before and after implementation of a Healthy Workplace Project intervention were used. Parameter distributions were developed from these data, as well as for micro-activity rates, contact surface areas, phage transfer efficiencies, and inactivation rates. Following the Monte Carlo simulations (n = 1,000), the estimated phage loading on hands was not significantly different from the loading of phage on hands measured in the experimental trials. The model was then used to demonstrate that the Healthy Workplace Project intervention significantly reduced risk of infection by 77% for rotavirus and rhinovirus. This is the first published study to successfully evaluate a model focused on the indirect transmission of viruses via hand contact with measured data and provide an assessment of the micro-activity approach to microbial risk evaluation.
• Lopez, G. U., Kitajima, M., Sexton, J. D., Gerba, C. P., & Reynolds, K. A. (2015). Risk of Campylobacter jejuni Infection from Preparing Raw Chicken in Domestic Kitchens and Reduction of Cross-contamination Using Disinfectant Wipes. Journal of Applied Microbiology, 119, 245-252.
• Lopez, G. u., Katajima, M., Sherchan, S. P., Sexton, J. D., Gerba, C. P., & Reynolds, K. A. (2015). Impact of Disinfectant Wipes on the Risk of Campylobacter jejuni Infection During Raw Chicken Preparation in Domestic Kitchens. Journal of Applied Microbiology. doi:10.1111/jam.12834 [Epub ahead of print]
• Reynolds, K. A., Beamer, P. I., Plotkin, K. R., Sifuentes, L. Y., Koenig, D. W., & Gerba, C. P. (2015). The healthy workplace project: Reduced viral exposure in an office setting. Archives of environmental & occupational health, 1-6.
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  Viral illnesses such as gastroenteritis and the common cold create a substantial burden in the workplace due to reduced productivity, increased absenteeism, and increased health care costs. Behaviors in the workplace contribute to the spread of human viruses via direct contact between hands, contaminated surfaces, and the mouth, eyes, and/or nose. This study assessed whether implementation of the Healthy Workplace Project (HWP) (providing hand sanitizers, disinfecting wipes, facial tissues, and use instructions) would reduce viral loads in an office setting of approximately 80 employees after seeding fomites and the hands of volunteer participants with an MS-2 phage tracer. The HWP significantly reduced viable phage detected on participants' hands, communal fomites, and personal fomites (p ≤ .010) in office environments and presents a cost-effective method for reducing the health and economic burden associated with viral illnesses in the workplace.
• Reynolds, K. A., Gerba, C. P., Sexton, J. D., Kitajima, M., & Lopez, G. U. (2015). Risk of Campylobacter jejuni Infection from Preparing Raw Chicken in Domestic Kitchens and Reduction of Cross-contamination Using Disinfectant Wipes. Journal of Applied Microbiology, 119, 245-252.
• Reynolds, K. A., Reynolds, K. A., Beamer, P. -., Beamer, P. -., Plotkin, K. R., Plotkin, K. R., Sifuentes, L. Y., Sifuentes, L. Y., Koenig, D. W., Koenig, D. W., Gerba, C. P., & Gerba, C. P. (2015). The Healthy Workplace Project: Reduced Viral Exposure in an Office Setting. Archives of Environmental and Occupational Health, doi:10.1080/19338244.2015.1058234.
• Sassi, H. P., Sifuentes, L. Y., Koenig, D. W., Nichols, E., Clark-Greuel, J., Wong, L. F., McGrath, K., Gerba, C. P., & Reynolds, K. A. (2015). Control of the spread of viruses in a long-term care facility using hygiene protocols. American journal of infection control, 43(7), 702-6.
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  Approximately 50% of norovirus cases in the United States occur in long-term care facilities; many incidences of rotavirus, sapovirus, and adenovirus also occur. The primary objectives of this study were to demonstrate movement of pathogenic viruses through a long-term care facility and to determine the impact of a hygiene intervention on viral transmission.
• Suppes, L. M., Ernst, K. C., Abrell, L. M., & Reynolds, K. A. (2015). Validation and Standardization of Swimming Exposure and Pool Operations Questionnaires. International Journal of Hygiene and Environmental Health..
• Valdez, M. K., Sexton, J. D., Lutz, E. A., & Reynolds, K. A. (2015). Spread of infectious microbes during emergency medical response. American journal of infection control, 43(6), 606-11.
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  To our knowledge, no studies to date demonstrate potential spread of microbes during actual emergency medical service (EMS) activities. Our study introduces a novel approach to identification of contributors to EMS environment contamination and development of infection control strategies, using a bacteriophage surrogate for pathogenic organisms.
• Verhougstraete, M., & Reynolds, K. A. (2015). Use of a portable air disinfecting system to remove seeded coliphage in hospital rooms. American Journal of Infection Control.
• Lopez, G. U., Kitajima, M., Havas, A., Gerba, C. P., & Reynolds, K. A. (2014). Evaluation of a Disinfectant Wipe Intervention on Fomite-to-Finger Microbial Transfer. Applied Environmental Microbiology, 80(10), 3113-3118.
• Lopez, G. U., Kitajima, M., Havas, A., Gerba, C. P., & Reynolds, K. A. (2014). Evaluation of a disinfectant wipe intervention on fomite-to-finger microbial transfer. Applied and environmental microbiology, 80(10), 3113-8.
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  Inanimate surfaces, or fomites, can serve as routes of transmission of enteric and respiratory pathogens. No previous studies have evaluated the impact of surface disinfection on the level of pathogen transfer from fomites to fingers. Thus, the present study investigated the change in microbial transfer from contaminated fomites to fingers following disinfecting wipe use. Escherichia coli (10(8) to 10(9) CFU/ml), Staphylococcus aureus (10(9) CFU/ml), Bacillus thuringiensis spores (10(7) to 10(8) CFU/ml), and poliovirus 1 (10(8) PFU/ml) were seeded on ceramic tile, laminate, and granite in 10-μl drops and allowed to dry for 30 min at a relative humidity of 15 to 32%. The seeded fomites were treated with a disinfectant wipe and allowed to dry for an additional 10 min. Fomite-to-finger transfer trials were conducted to measure concentrations of transferred microorganisms on the fingers after the disinfectant wipe intervention. The mean log10 reduction of the test microorganisms on fomites by the disinfectant wipe treatment varied from 1.9 to 5.0, depending on the microorganism and the fomite. Microbial transfer from disinfectant-wipe-treated fomites was lower (up to
• Lopez, G. U., Lopez, G. U., Kitajima, M., Kitajima, M., Sexton, J. D., Sexton, J. D., Gerba, C. P., Gerba, C. P., Reynolds, K. A., Reynolds, K. A., Lopez, G. U., Kitajima, M., Sexton, J. D., Gerba, C. P., & Reynolds, K. A. (2015). Risk of Campylobacter jejuni Infection from Preparing Raw Chicken in Domestic Kitchens and Reduction of Cross-contamination Using Disinfectant Wipes. Journal of Applied Microbiology, 119, 245-252.
• Reynolds, K. A. (2014). Do You Know Where Your Phthalates Are?. Water Conditioning and Purification International, 56(3), 66-68.
• Reynolds, K. A. (2014). Enterovirus 68 and the Recent Emergence of a Polio-Like Syndrome. Water Conditioning and Purification International, 56(4), 50-52.
• Reynolds, K. A. (2014). Guidance for the POU Industry: AWWA’s State of the Water Industry Report. Water Conditioning and Purification International., 56(9), 52-54.
• Reynolds, K. A. (2014). Health Risks Associated with Cross-connections in Drinking Water Supply. Water Conditioning and Purification International, 56(7), 50-52.
• Reynolds, K. A. (2014). Is Ebola a Waterborne Virus?. Water Conditioning and Purification International, 56(11), 46-48.
• Reynolds, K. A. (2014). Major U.S. Cities Running Out of Water.. Water Conditioning and Purification International, 56(1), 44-46.
• Reynolds, K. A. (2014). New Waterborne Risks: A Case Study of West Virginia’s Chemical Spill. Water Conditioning and Purification International, 56(5), 50-53.
• Reynolds, K. A. (2014). Sewage Overflows Impact US Cities/Public Health. Water Conditioning and Purification International, 56(12), 48-50.
• Reynolds, K. A. (2014). Threat Assessment of Free-Living Amoeba in Drinking Water. Water Conditioning and Purification International, 56(8), 44-46.
• Reynolds, K. A. (2014). Urgent Threats from Antibiotic-Resistant Organisms. Water Conditioning and Purification International, 56(6), 48-50.
• Reynolds, K. A. (2014). Water-based Virus May Cause Rheumatoid Arthritis. Water Conditioning and Purification International, 56(2), 58-62.
• Reynolds, K. A. (2014). Waterborne Contaminants and Increasing Incidence of Irritable Bowel Syndrome. Water Conditioning and Purification International., 56(10), 54-56.
• Sexton, J. D., Sexton, J. D., & Reynolds, K. A. (2014). Occurrence and Control of Pathogens on Soft Surfaces in the Healthcare Environment. American Journal of Infection Control, 42(6), S43. doi:10.1016/j.ajic.2014.03.113
• Sifuentes, L. Y., Koenig, D. W., Phillips, R. L., Reynolds, K. A., & Gerba, C. P. (2014). Use of hygiene protocols to control the spread of viruses in a hotel. Food and environmental virology, 6(3), 175-81.
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  The goals of this study were to observe the spread of viruses in a hotel setting and to assess the effectiveness of a hygiene intervention in reducing their spread. Selected fomites in one hotel room were inoculated with bacteriophage ϕx-174, and fomites in a conference center within the same hotel were inoculated using bacteriophage MS2. Cleaning of the contaminated room resulted in the spread of viruses to other rooms by the housekeeping staff. Furthermore, viruses were transferred by hotel guests to the conference center and a communal kitchen area. Additionally, conference attendees transferred viruses from the conference center to their hotel rooms and a communal kitchen area. This study demonstrated how viruses can be spread throughout a hotel setting by both housekeepers and guests. A hygiene intervention, which included providing hand hygiene products and facial tissues to the guests and disinfecting solutions with disposable wipes to the housekeeping staff, was successful in reducing the spread of viruses between the hotel guest rooms and conference center. The hygiene intervention resulted in significantly reduced transfer of the ϕx-174 between the contaminated hotel room and other hotel rooms, communal areas, and the conference center (p = 0.02).
• Sifuentes, L. Y., Koenig, D. W., Reynolds, K. A., & Gerba, C. P. (2014). Use of Hygiene Protocols to Control the Spread of Viruses in a Hotel. Food and Environmental Virology, 6(3), 175-181.
• Suppes, L. M., & Reynolds, K. A. (2014). Swimmer Recall on a Recreational Waterborne Illness Outbreak Questionnaire. Microchemical Journal, 112(1), 150-152.
• Suppes, L. M., Abrell, L. M., A, D. P., Gerba, C. P., & Reynolds, K. A. (2014). Assessment of Swimmer Head Submersion Exposures and Pool Water Ingestion.. Journal of Water and Health, 12(2), 269-279.
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  ABSTRACTEnteric pathogens in pool water can be unintentionally ingested during swimming, increasing the likelihood of acute gastrointestinal illness (AGI). AGI cases in outbreaks are more likely to submerge heads than non-cases, but an association is unknown since outbreak data are self-reported and prone to bias. In the present study, head submersion frequency and duration were observed and analyzed for associations with pool water ingestion measured using ultra high pressure liquid chromatography – tandem mass spectrometry. Frequency of splashes to the face was also quantified. Reliable tools that assess activities associated with pool water ingestion are needed to identify ingestion risk factors and at-risk populations. Objectives were to determine if the observed activities were associated with ingestion, and to test environmental sensor and videography assessment tools. Greater frequency and duration of head submersion were not associated with ingestion, but frequency of splashes to the face, leisurely swimming, and being ≤18 were. Videography was validated for assessing swimmer head submersion frequency. Results demonstrate ingestion risk factors can be identified using videography and urine analysis techniques. Expanding surveys to include questions on leisure swimming participation and frequency of splashes to the face is recommended to improve exposure assessment during outbreak investigations.Keywords: exposure factor; head submersion; ingestion; pool; recreational water; swimming
• Suppes, L. M., Abrell, L., Dufour, A. P., & Reynolds, K. A. (2014). Assessment of swimmer behaviors on pool water ingestion. Journal of water and health, 12(2), 269-79.
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  Enteric pathogens in pool water can be unintentionally ingested during swimming, increasing the likelihood of acute gastrointestinal illness (AGI). AGI cases in outbreaks are more likely to submerge heads than non-cases, but an association is unknown since outbreak data are self-reported and prone to bias. In the present study, head submersion frequency and duration were observed and analyzed for associations with pool water ingestion measured using ultra high pressure liquid chromatography - tandem mass spectrometry. Frequency of splashes to the face was also quantified. Reliable tools that assess activities associated with pool water ingestion are needed to identify ingestion risk factors and at-risk populations. Objectives were to determine if the observed activities were associated with ingestion, and to test environmental sensor and videography assessment tools. Greater frequency and duration of head submersion were not associated with ingestion, but frequency of splashes to the face, leisurely swimming, and being ≤18 were. Videography was validated for assessing swimmer head submersion frequency. Results demonstrate ingestion risk factors can be identified using videography and urine analysis techniques. Expanding surveys to include questions on leisure swimming participation and frequency of splashes to the face is recommended to improve exposure assessment during outbreak investigations.
• Reynolds, K. A. (2013). Aichi Virus: Possible Agent of Unexplained Cases of Waterborne Diarrhea. Water Conditioning and Purification International.
• Reynolds, K. A. (2013). An Ongoing Cyclospora Outbreak in the U.S.- Source Currently Unknown. Water Conditioning and Purification International.
• Reynolds, K. A. (2013). Boil Water Orders Abound in the U.S.. Water Conditioning and Purification International.
• Reynolds, K. A. (2013). Deadly Legionella: Commonly Found in U.S. Water SystemsWater. Water Conditioning & Purification International.
• Reynolds, K. A. (2013). Evidence of Drug-Resistant Bacteria in Water. Water Conditioning and Purification International.
• Reynolds, K. A. (2013). Hitting a Moving Target: Regulation of 1,4-Dioxane in Drinking Water. Water Conditioning and Purification International.
• Reynolds, K. A. (2013). Newly Released Review on Drinking Water Outbreak Causes. Water Conditioning and Purification International.
• Reynolds, K. A. (2013). No Ticket Needed: Dust Plumes Carry Microbes Around the Globe. Water Conditioning and Purification International.
• Reynolds, K. A. (2013). Recognized Health Burdens Drive Drinking Water Regulation Revisions. Water Conditioning and Purification International.
• Reynolds, K. A. (2013). U.S. Public Water Supplies: First Positive Confirmations of Deadly Amoeba. Water Conditioning and Purification International.
• Reynolds, K. A. (2013). – Exploring Nanosponge Technologies for Water Treatment. Water Conditioning and Purification International.
• Reynolds, K. A. (2013). – The Chromium VI Calamity. Water Conditioning and Purification International.
• Reynolds, K. A., Abrell, L., Suppes, L. M., & Dufour, A. P. (2013). Assessment of swimmer behaviors on pool water ingestion. Journal of Water and Health, 12(2), 269-279. doi:10.2166/wh.2013.123
• Soto Beltran, M., Mena, K. D., Gerba, C. P., Tarwater, P., Reynolds, K. A., & Chaidez, C. (2013). Risk assessment of Listeria monocytogenes in queso fresco in Culiacan, Mexico. Journal of Microbiology Research.
• Nordstrom, J. M., Reynolds, K. A., & Gerba, C. P. (2012). Comparison of bacteria on new, disposable, laundered, and unlaundered hospital scrubs. American journal of infection control, 40(6), 539-43.
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  As a cost-saving measure, an increasing number of hospitals allow personnel to launder their uniforms, lab coats, and operating room scrubs at home. With rising nosocomial infection rates and increasing levels of multidrug-resistant bacteria in hospital settings, uniform contamination may be an environmental factor in the spread of infection.
• Reynolds, K. A., Boone, S., Bright, K. R., & Gerba, C. P. (2012). Occurrence of household mold and efficacy of sodium hypochlorite disinfectant. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE, 9(11), 663-9. doi:https://doi.org/10.1080/15459624.2012.724650
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  The occurrence and distribution of mold on household surfaces and the efficacy of bleach-based (sodium hypochlorite, NaOCl) disinfectants on mold viability and allergenicity was documented. Household microenvironments prone to increased moisture were specifically targeted. Using the sticky tape method, 1330 samples were collected from non-porous indoor surfaces of 160 homes across the United States, and analyzed for mold. Homes were randomly selected and recruited via phone interviews. Culture and immunoassays were used to measure the viability and reduction of allergenic properties of Aspergillus fumigatus following 2.4% NaOCl treatment. All homes and 72.9% of surfaces tested positive for mold. Windowsills were the most frequently contaminated site (87.5%) and Cladosporium the most commonly identified mold (31.0%). Five-minute exposures to 2.4% NaOCl resulted in a >3 to >6-log₁₀ reduction of culturable mold counts in controlled laboratory studies. Organisms were nonculturable after 5- and 10-min contact times on non-porous and porous ceramic carriers, respectively, and A. fumigatus spore-eluted allergen levels were reduced by an average 95.8% in 30 sec, as indicated by immunoassay. All homes are contaminated with some level of mold, and regrowth is likely in moisture-prone microenvironments. The use of low concentrations (2.4%) of NaOCl for the reduction of culturable indoor mold and related allergens is effective and recommended.
• Reynolds, K. A., Boone, S., Bright, K. R., & Gerba, C. P. (2012). Occurrence of household mold and efficacy of sodium hypochlorite disinfectant. Journal of occupational and environmental hygiene, 9(11), 663-9.
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  The occurrence and distribution of mold on household surfaces and the efficacy of bleach-based (sodium hypochlorite, NaOCl) disinfectants on mold viability and allergenicity was documented. Household microenvironments prone to increased moisture were specifically targeted. Using the sticky tape method, 1330 samples were collected from non-porous indoor surfaces of 160 homes across the United States, and analyzed for mold. Homes were randomly selected and recruited via phone interviews. Culture and immunoassays were used to measure the viability and reduction of allergenic properties of Aspergillus fumigatus following 2.4% NaOCl treatment. All homes and 72.9% of surfaces tested positive for mold. Windowsills were the most frequently contaminated site (87.5%) and Cladosporium the most commonly identified mold (31.0%). Five-minute exposures to 2.4% NaOCl resulted in a >3 to >6-log₁₀ reduction of culturable mold counts in controlled laboratory studies. Organisms were nonculturable after 5- and 10-min contact times on non-porous and porous ceramic carriers, respectively, and A. fumigatus spore-eluted allergen levels were reduced by an average 95.8% in 30 sec, as indicated by immunoassay. All homes are contaminated with some level of mold, and regrowth is likely in moisture-prone microenvironments. The use of low concentrations (2.4%) of NaOCl for the reduction of culturable indoor mold and related allergens is effective and recommended.
• Reynolds, K. A., Mena, K. D., & Giovanni, G. D. (2012). Cryptosporidium and Giardia zoonoses: Minimizing health risks from food animal production. Cab Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources, 7(008), 1-7. doi:10.1079/pavsnnr20127008
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  Abstract More than 10 years ago, food-borne pathogens were estimated to cause 76 000 illnesses and 5 000 deaths in the USA alone. Given the under-reporting of food-borne illnesses, the numbers of illnesses and deaths associated with food are actually higher. Food-borne pathogens continue to impact public health through worldwide disease outbreaks as they have many opportunities to enter the food chain - from the pre-harvest environment to the consumer. With over half of all disease-causing micro-organisms having the ability to be transmitted zoonotically, food animal production is a key source of pathogens in the farm-to-fork continuum. The protozoan parasites, Cryptosporidium and Giardia, have both been implicated in food-borne disease, and have the potential to be transmitted zoonotically in the farm environment. Farm management strategies have been developed to minimize the transmission of protozoa (from animals) that may infect farm workers, and contaminate nearby waterways and food crops. Such strategies target protecting the health of the herd, preventing (oo)cyst transmission to surface water and vegetable crops, and providing education to animal husbandry personnel and veterinarians on best management practices. To fully address the challenges associated with food safety, post-harvest control measures should also be implemented.
• Lee-Montiel, F. T., Reynolds, K. A., & Riley, M. R. (2011). Detection and quantification of poliovirus infection using FTIR spectroscopy and cell culture. Journal of biological engineering, 5, 16.
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  In a globalized word, prevention of infectious diseases is a major challenge. Rapid detection of viable virus particles in water and other environmental samples is essential to public health risk assessment, homeland security and environmental protection. Current virus detection methods, especially assessing viral infectivity, are complex and time-consuming, making point-of-care detection a challenge. Faster, more sensitive, highly specific methods are needed to quantify potentially hazardous viral pathogens and to determine if suspected materials contain viable viral particles. Fourier transform infrared (FTIR) spectroscopy combined with cellular-based sensing, may offer a precise way to detect specific viruses. This approach utilizes infrared light to monitor changes in molecular components of cells by tracking changes in absorbance patterns produced following virus infection. In this work poliovirus (PV1) was used to evaluate the utility of FTIR spectroscopy with cell culture for rapid detection of infective virus particles.
• Reynolds, K. A., Pepper, I. L., Mahalanabis, M., & Gerba, C. P. (2010). Comparison of Multiple Passage Integrated Cell Culture-PCR and Cytopathogenic Effects in Cell Culture for the Assessment of Poliovirus Survival in Water. Food and Environmental Virology, 2(4), 225-230. doi:10.1007/s12560-010-9051-4
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  The goal of this study was to determine if a cytopathogenic effects (CPE) cell culture assay and an integrated cell culture PCR (ICC-PCR) assay would yield similar or different results when used to assess virus survival in water. Poliovirus type 1 was added to dechlorinated tapwater and stored at room temperature (22.5–24°C) for a total of 50 days. Samples were assayed at defined time intervals by the most probable number (MPN) method on Buffalo green monkey kidney cells (BGM) by CPE and additionally by ICC-PCR. Monolayers that were CPE negative on first passage were passed onto fresh monolayers of cells for a second and third time if still negative. By CPE assay, second passage was observed to yield a greater titer (2,300 vs. 24,000 MPN/ml) and third passage also resulted in an increased titer. ICC-PCR proved to be a more rapid and sensitive method than conventional cell culture for determining virus inactivation rates in water. Poliovirus survived in tapwater for up to 32 days, as assessed by both third passage ICC-PCR and CPE. There was no statistical difference in the inactivation rates between the two methods. To determine the total number of infectious viruses, these findings indicate the need for performing three cell culture passages or, alternatively, ICC-PCR on first passage.
• Reynolds, K., Sexton, J. D., & Reynolds, K. A. (2010). Exposure of emergency medical responders to methicillin-resistant Staphylococcus aureus. American journal of infection control, 38(5).
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  Methicillin-resistant Staphylococcus aureus (MRSA) infections result in 19,000 deaths a year in the United States. Epidemiologic studies have shown that community-acquired infections are increasing dramatically, and strains typical of community infections are increasingly detected in hospital populations. Emergency medical responders (EMR) are exposed to both community and hospital MRSA patients, which, combined with their communal lifestyles in fire stations, results in higher risk of exposure. This study determined the occurrence and frequency of MRSA and other bacterial indicators on environmental surfaces in fire stations, training sites, and offices of EMR.
• Roberts, M. C., Meschke, J. S., Soge, O. O., & Reynolds, K. A. (2010). Comment on MRSA studies in high school wrestling and athletic training facilities. Journal of environmental health, 72(9), 48-9; author reply 49.
• Yang, Z., Fah, M. K., Reynolds, K. A., Sexton, J. D., Riley, M. R., Anne, M., Bureau, B., & Lucas, P. (2010). Opto-electrophoretic detection of bio-molecules using conducting chalcogenide glass sensors. Optics express, 18(25), 26754-9.
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  Novel telluride glasses with high electrical conductivity, wide infrared transparency and good resistance to crystallization are used to design an opto-electrophoretic sensor for detection and identification of hazardous microorganisms. The sensor is based on an attenuated total reflectance element made of Ge-As-Te glass that serves as both an optical sensing zone and an electrode for driving the migration of bio-molecules within the evanescent wave of the sensor. An electric field is applied between the optical element and a counter electrode in order to induce the migration of bio-molecules carrying surface charges. The effect of concentration and applied voltage is tested and the migration effect is shown to be reversible upon switching the electric field. The collected signal is of high quality and can be used to identify different bacterial genus through statistical spectral analysis. This technique therefore provides the ability to detect hazardous microorganisms with high specificity and high sensitivity in aqueous environments. This has great potential for online monitoring of water quality.
• Andrade, C., Champagne, S., Caruso, D., Foster, K., & Reynolds, K. (2009). Methicillin-resistant Staphylococcus aureus: an assessment of environmental contamination in a burn center. American journal of infection control, 37(6), 515-7.
• Reynolds, K., Miles, S. L., Gerba, C. P., Pepper, I. L., & Reynolds, K. A. (2009). Point-of-Use drinking water devices for assessing microbial contamination in finished water and distribution systems. Environmental science & technology, 43(5).
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  The objective of this study was to develop a method to monitor the microbial quality of treated drinking water at the tap utilizing point-of-use filter systems that are placed in water vending machines. Such vending machines have high-volume water throughput and allow for an evaluation of the occurrence of human enteric pathogens and fecal indicator bacteria in tap water over extended time periods. Seeded experiments, using Escherichia coli and bacteriophage MS-2, were performed on (i) new filters, (ii) artificially aged filters, and (iii) filters that had been used in the field (naturally aged filters) to evaluate the efficiency of recovery of these organisms from the three-component filter set (30 microm, 5 mirom, solid block carbon (SBC)) by evaluating each filter independently. SBC filters had the highest recovery of the organisms, averaging recovery of 27% and 5% for E. coli and MS-2, respectively. Subsequently, tapwatersupplieswere monitored in vending machinesthroughout Southern Arizona using SBC filters as a monitoring tool. A total of 48 filters from 41 unique site locations were surveyed for the presence of total coliforms, E. coli, enterococci, Cryptosporidium, enteroviruses, and noroviruses. Organisms were detected following the passage of large volumes of water ranging from 1000 to 17,000 L through the filters. Out of 48 SBC filters 54.2% were positive for at least one organism. The number of filters positive for total coliforms, E. coli, enterococci, and enterovirus was 13, 5, 19, and 3, respectively, corresponding to 27.1%, 10.4%, 39.6%, and 6.3% of the total filters. No filters were positive for noroviruses or Cryptosporidium. These results suggest that the SBC filter can be used to monitor large volumes of treated drinking water and detect the incidence of indicators and pathogens that may be present at low concentrations. These data show that post-treated water often contains water quality indicator and pathogenic organisms at the tap, and therefore, monitoring with this method would be beneficial to the community as it allows for an assessment of exposure to pathogens and associative risks. This monitoring tool will also aid in the tracking of outbreaks and the determination of the microbial pathogen load during all stages of an outbreak as a filter can be installed and retrieved at the point-of-use at anytime during an outbreak.
• Vargas, C. A., Wilhelm, A. A., Williams, J., Lucas, P., Reynolds, K. A., & Riley, M. R. (2009). Integrated capture and spectroscopic detection of viruses. Applied and environmental microbiology, 75(20), 6431-40.
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  The goal of this work is to develop an online monitoring scheme for detection of viruses in flowing drinking water. The approach applies an electrodeposition process that is similar to the use of charged membrane filters previously employed for collection of viruses from aqueous samples. In the present approach, charged materials are driven onto a robust optical sensing element which has high transparency to infrared light. A spectroscopic measurement is performed using the evanescent wave that penetrates no more than 1 mum from the surface of an infrared optical element in an attenuated total reflectance measurement scheme. The infrared measurement provides quantitative information on the amount and identity of material deposited from the water. Initial studies of this sensing scheme used proteins reversibly electrodeposited onto germanium chips. The results of those studies were applied to design a method for collection of viruses onto an attenuated total reflectance crystal. Spectral signatures can be discriminated between three types of protein and two viruses. There is the potential to remove deposited material by reversing the voltage polarity. This work demonstrates a novel and practical scheme for detection of viruses in water systems with potential application to near-continual, automated monitoring of municipal drinking water.
• Lucas, P., Riley, M. R., Wilhelm, A. A., Riley, M. R., Reynolds, K. A., & Lucas, P. (2008). Integrated capture and spectroscopic detection of viruses in an aqueous environment. Proceedings of SPIE, 6852. doi:10.1117/12.774540
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  A new approach to virus detection in an aqueous environment has been developed using the electrophoretic deposition of protein and viruses on a charged surface for in situ infrared characterization and identification. In this study, a potential was applied across a germanium ATR crystal, which acted as the anode, and an indium tin oxide (ITO) plate, which acted as the cathode in the electrodeposition setup. Sample aqueous solutions were placed between the germanium and the ITO with different concentrations of the protein bovine serum albumin (BSA) and the virus MS2, in tap water. The pH of the tap water was above the isoelectric point of the virus and the protein, resulting in a net negative charge for both. The negatively charged protein and virus were then driven to the surface of the positively charged germanium ATR crystal, once a potential was applied to the system. FTIR/ATR was used before and throughout electrodeposition to enable the in situ observation of the deposition with time. In this study, we evaluate the capture efficiency, compared to control experiments with no applied voltage, and the feasibility of using this approach for the collection and quantification of proteins and viruses from water samples. This technique resulted in the successful deposition of BSA, and MS2 with an applied voltage of only 1.1V. Furthermore, based on the analysis of the ATR spectra, distinct spectral features were identified for the protein and virus showing the potential for identification and characterization of biological molecules in an aqueous environment.
• Reynolds, K. A., Mena, K. D., & Gerba, C. P. (2008). Risk of waterborne illness via drinking water in the United States. Reviews of environmental contamination and toxicology, 192, 117-58.
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  Outbreaks of disease attributable to drinking water are not common in the U.S., but they do still occur and can lead to serious acute, chronic, or sometimes fatal health consequences, particularly in sensitive and immunocompromised populations. From 1971 to 2002, there were 764 documented waterborne outbreaks associated with drinking water, resulting in 575,457 cases of illness and 79 deaths (Blackburn et al. 2004; Calderon 2004); however, the true impact of disease is estimated to be much higher. If properly applied, current protocols in municipal water treatment are effective at eliminating pathogens from water. However, inadequate, interrupted, or intermittent treatment has repeatedly been associated with waterborne disease outbreaks. Contamination is not evenly distributed but rather affected by the number of pathogens in the source water, the age of the distribution system, the quality of the delivered water, and climatic events that can tax treatment plant operations. Private water supplies are not regulated by the USEPA and are generally not treated or monitored, although very few of the municipal systems involved in documented outbreaks exceeded the USEPA's total coliform standard in the preceding 12 mon (Craun et al. 2002). We provide here estimates of waterborne infection and illness risks in the U.S. based on the total number of water systems, source water type, and total populations exposed. Furthermore, we evaluated all possible illnesses associated with the microbial infection and not just gastroenteritis. Our results indicate that 10.7 M infections/yr and 5.4 M illnesses/yr occur in populations served by community groundwater systems; 2.2 M infections/yr and 1.1 M illnesses/yr occur in noncommunity groundwater systems; and 26.0 M infections/yr and 13.0 M illnesses/yr occur in municipal surface water systems. The total estimated number of waterborne illnesses/yr in the U.S. is therefore estimated to be 19.5 M/yr. Others have recently estimated waterborne illness rates of 12M cases/yr (Colford et al. 2006) and 16 M cases/yr (Messner et al. 2006), yet our estimate considers all health outcomes associated with exposure to pathogens in drinking water rather than only gastrointestinal illness. Drinking water outbreaks exemplify known breaches in municipal water treatment and distribution processes and the failure of regulatory requirements to ensure water that is free of human pathogens. Water purification technologies applied at the point-of-use (POU) can be effective for limiting the effects of source water contamination, treatment plant inadequacies, minor intrusions in the distribution system, or deliberate posttreatment acts (i.e., bioterrorism). Epidemiological studies are conflicting on the benefits of POU water treatment. One prospective intervention study found that consumers of reverse-osmosis (POU) filtered water had 20%-35% less gastrointestinal illnesses than those consuming regular tap water, with an excess of 14% of illness due to contaminants introduced in the distribution system (Payment 1991, 1997). Two other studies using randomized, blinded, controlled trials determined that the risks were equal among groups supplied with POU-treated water compared to untreated tap water (Hellard et al. 2001; Colford et al. 2003). For immunocompromised populations, POU water treatment devices are recommended by the CDC and USEPA as one treatment option for reducing risks of Cryptosporidium and other types of infectious agents transmitted by drinking water. Other populations, including those experiencing "normal" life stages such as pregnancy, or those very young or very old, might also benefit from the utilization of additional water treatment options beyond the current multibarrier approach of municipal water treatment.
• Reynolds, K. A., Watt, P. M., Boone, S. A., & Gerba, C. P. (2005). Occurrence of bacteria and biochemical markers on public surfaces. International journal of environmental health research, 15(3), 225-34.
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  From 1999-2003, the hygiene of 1061 environmental surfaces from shopping, daycare, and office environments, personal items, and miscellaneous activities (i.e., gymnasiums, airports, movie theaters, restaurants, etc.), in four US cities, was monitored. Samples were analyzed for fecal and total coliform bacteria, protein, and biochemical markers. Biochemical markers, i.e., hemoglobin (blood marker), amylase (mucus, saliva, sweat, and urine marker), and urea (urine and sweat marker) were detected on 3% (26/801); 15% (120/801), and 6% (48/801) of the surfaces, respectively. Protein (general hygiene marker) levels > or = 200 microg/10 cm2 were present on 26% (200/801) of the surfaces tested. Surfaces from children's playground equipment and daycare centers were the most frequently contaminated (biochemical markers on 36%; 15/42 and 46%; 25/54, respectively). Surfaces from the shopping, miscellaneous activities, and office environments were positive for biochemical markers with a frequency of 21% (69/333), 21% (66/308), and 11% (12/105), respectively). Sixty samples were analyzed for biochemical markers and bacteria. Total and fecal coliforms were detected on 20% (12/60) and 7% (4/ 60) of the surfaces, respectively. Half and one-third of the sites positive for biochemical markers were also positive for total and fecal coliforms, respectively. Artificial contamination of public surfaces with an invisible fluorescent tracer showed that contamination from outside surfaces was transferred to 86% (30/ 35) of exposed individual's hands and 82% (29/35) tracked the tracer to their home or personal belongings hours later. Results provide information on the relative hygiene of commonly encountered public surfaces and aid in the identification of priority environments where contaminant occurrence and risk of exposure may be greatest. Children's playground equipment is identified as a priority surface for additional research on the occurrence of and potential exposure to infectious disease causing agents.
• Bright, K. R., Reynolds, K. A., Gerba, C. P., Bright, K. R., & Boone, S. A. (2004). Efficacy of sodium hypochlorite disinfectant on the viability and allergenic properties of household mold. The Journal of Allergy and Clinical Immunology, 113(2), S180. doi:10.1016/j.jaci.2004.01.082
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  Abstract Rationale Many fungi colonize indoor environments and produce allergenic proteins that cause adverse health symptoms in sensitive individuals. The effect of sodium hypochlorite (2.4% NaOCl) disinfectant on fungal growth and the presence of allergenic properties was evaluated. Methods Environmental and laboratory isolates of common indoor mold contaminants ( Penicillium , Cladosporium , Mucor , Rhizopus , Stachybotrys , Alternaria , Aspergillus , Helminthosporium , and Trichophyton ) were grown to sporulation, purified, dried on sterile ceramic porous and non-porous carriers, and treated with 2.4% NaOCl for up to 10 min. Volunteer's showers were monitored, for 2 weeks to determine the rate of mold regrowth following disinfectant treatment. ELISA tests measured the ability of NaOCl to reduce the allergenic properties of Aspergillus fumigatus following 30 sec, 1 min, and 5 min exposures. Results 2.4% NaOCl reduced total mold counts in home showers by >4 logs after 5 min exposures. In controlled laboratory studies, home mold isolates were reduced by >5 logs following 5 min exposures with 2.4% NaOCl. Test organisms were not culturable in 10 out of 10 trials after 5 and 10 min contact times in non-porous and porous ceramic carriers, respectively. NaOCl treatment reduced A. fumigatus allergen levels by >90% in as little as 30 seconds. Conclusions Low concentrations (2.4%) of NaOCl, common to household disinfectants, are effective at reducing mold from indoor surfaces, to undetectable levels, in both real-time and seeded laboratory studies. In addition, NaOCl effectively fragments the proteins responsible for the allergenic properties of indoor mold.
• Reynolds, K. A., & Reynolds, K. A. (2004). Coliform bacteria: A failed indicator of water quality?. Water Conditioning and Purification International.
• Reynolds, K., & Reynolds, K. A. (2004). Integrated cell culture/PCR for detection of enteric viruses in environmental samples. Methods in molecular biology (Clifton, N.J.), 268.
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  Recently, an integrated cell culture/polymerase chain reaction (ICC/PCR) technique has been developed for the detection of viruses in environmental samples providing a reliable method for practical analysis and direct monitoring of environmental samples for viral pathogens. CC/PCR allows for detection of infectious viruses in hours to days compared with the days or weeks necessary with cell culture alone. Bacterial indicator organisms are commonly used to evaluate environmental samples with respect to fecal contamination and potential public health impacts. These organisms do not correlate well with the presence of viruses, but a rapid, reliable method was not previously available for direct virus testing. Using ICC/PCR, environmental samples may be directly surveyed for pathogenic viruses, in a timely manner. Direct virus analysis will lead to better assessment of the presence and risk of human enteric viruses in the environment, so that control measures may be developed with true virus occurrence data. The ICC/PCR approach combines two previously applied virus detection methods, conventional cell culture and PCR amplification, utilizing the major advantages and overcoming the major limitations of each methodology when used alone. Cell culture assay is the standard method for the detection of viable human viruses (i.e., poliovirus, coxsackievirus, echovirus, adenovirus, hepatitis A virus, reovirus, and rotavirus) in environmental samples, serving as the method against which all newer technologies are evaluated. Although cell culture is theoretically capable of detecting a single viable virus in relatively large volumes of sample, the time required for confirmed results with conventional cell culture makes it an impractical method for routine monitoring of environmental samples. Furthermore, cell culture does not detect noncytopathogenic viruses (viruses that are viable, infecting cells, and continually spreading to neighboring cells but that do not cause a visible cytopathogenic effect [CPE] on the cell monolayer). Rotavirus and most wild-type hepatitis A viruses (HAV) are infectious to cell cultures but do not produce a clear CPE.
• Reynolds, K., Gerba, C., Kuwahara, S., & Tanner, B. (2004). Evaluation of electrochemically generated ozone for the disinfection of water and wastewater. Water Science and Technology, 50(1), 19-25. doi:10.2166/wst.2004.0007
• Reynolds, K., Tanner, B. D., Kuwahara, S., Gerba, C. P., & Reynolds, K. A. (2004). Evaluation of electrochemically generated ozone for the disinfection of water and wastewater. Water science and technology : a journal of the International Association on Water Pollution Research, 50(1).
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  Effective wastewater treatment is critical to public health and well-being. This is especially true in developing countries, where disinfection of wastewater is frequently inadequate. People who live in these areas may benefit from wastewater disinfection using ozone. This study evaluated the ability of a new electrochemical process of ozone generation, which produced ozone continuously at high pressure and concentration by the electrolysis of water, to disinfect tap water and secondarily treated wastewater. Inactivation of Klebsiella terrigena, Escherichia coli, MS2 bacteriophage and poliovirus 1 was evaluated first in reverse osmosis (RO) treated water. Inactivation of K. terrigena (6-log), E. coli (6-log), MS2 (6-log) and poliovirus 1 (>3-log) was observed after 1 min of ozonation in a 1 L batch reactor. Experiments were then performed to assess the microbiological impact of disinfection using ozone on secondarily treated municipal wastewater. The effect of ozonation on wastewater was determined for total and faecal coliforms, bacteriophages and heterotrophic plate count (HPC) bacteria. Electrochemical ozone generators provided an effective, rapid and low-cost method of wastewater disinfection. Based on the results of this research, electrochemically generated ozone would be well suited to remote, small-scale, disinfection operations and may provide a feasible means of wastewater disinfection in developing countries.
• Reynolds, K. A., Gerba, C. P., & Boone, S. A. (2003). Occurrence and distribution of mold in the home environment. The Journal of Allergy and Clinical Immunology, 111(2), S239. doi:10.1016/s0091-6749(03)80844-8
• Reynolds, K. A., Pepper, I. L., Gerba, C. P., & Abbaszadegan, M. (2001). ICC/PCR detection of enteroviruses and hepatitis A virus in environmental samples.. Canadian Journal of Microbiology, 47(2), 153-157. doi:10.1139/w00-134
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  This study applied the integrated cell culture/polymerase chain reaction methodology (ICC/PCR) for rapid and specific detection of both cytopathogenic and noncytopathogenic viruses. Results of this study showed that the use of direct RT-PCR or conventional cell culture alone may yield erroneous results with the analysis of environmental samples. The purpose of this study was to compare cultural, molecular, and combined assays for the most effective method of virus detection in variable environmental samples. Using ICC/PCR, stock enterovirus inocula of > or =10 PFU were PCR positive in at least 4/5 replicate flasks after only 5 h of incubation in cell culture, and in all flasks after > or =10 h. An inoculum of one PFU was detected by PCR after 20 h of cell culture incubation while for concentrations of virus below one PFU, 25 h of incubation was sufficient. Similarly, hepatitis A virus (HAV) inocula of 100 MPN/flask, produced indeterminate CPE in cell culture, but were clearly detected by ICC/PCR following 48 h of incubation. Lower levels of HAV, 1 and 10 MPN, were detected by ICC/PCR after 96 to 72 h of incubation, respectively. Cell culture lysates from 11 environmental sample concentrates of sewage, marine water, and surface drinking water sources, were positive for enteroviruses by ICC/PCR compared to 3 positive by direct RT-PCR alone. Results from ICC/PCR eventually agreed with cell culture but required < or =48 h of incubation, compared to as long as 3 weeks for CPE following incubation with BGM and FRhK cells.
• Reynolds, K. A., Pepper, I. L., Gerba, C. P., & Blackmer, F. (2000). Use of integrated cell culture-PCR to evaluate the effectiveness of poliovirus inactivation by chlorine.. Applied and environmental microbiology, 66(5), 2267-8. doi:10.1128/aem.66.5.2267-2268.2000
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  Current standards, based on cell culture assay, indicate that poliovirus is inactivated by 0.5 mg of free chlorine per liter after 2 min; however, integrated cell culture-PCR detected viruses for up to 8 min of exposure to the same chlorine concentration, requiring 10 min for complete inactivation. Thus, the contact time for chlorine disinfection of poliovirus is up to five times greater than previously thought.
• Roll, K. P., Reynolds, K. A., Pepper, I. L., Gerba, C. P., & Fujioka, R. S. (1998). Incidence of enteroviruses in Mamala Bay, Hawaii using cell culture and direct polymerase chain reaction methodologies. Canadian Journal of Microbiology, 44(6), 598-604. doi:10.1139/w98-040
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  The consequence of point and nonpoint pollution sources, discharged into marine waters, on public recreational beaches in Mamala Bay, Hawaii was evaluated using virus cell culture and direct reverse transcriptase-polymerase chain reaction (RT-PCR). Twelve sites, nine marine, two freshwater (one stream and one canal), and one sewage, were assessed either quarterly or monthly for 1 year to detect the presence of human enteric viruses. Water samples were concentrated from initial volumes of 400 L to final volumes of 30 mL using Filterite electronegative cartridge filters and a modified beef extract elution procedure. Cell culture was applied using the Buffalo Green Monkey kidney cell line to analyze samples for enteroviruses. Positive samples were also evaluated by RT-PCR, using enterovirus-specific primers. Levels of RT-PCR inhibition varied with each concentrated sample. Resin column purification increased PCR detection sensitivity by at least one order of magnitude in a variety of sewage outfall and recreational marine water samples but not in the freshwater canal samples. Using cell culture, viable enteroviruses were found in 50 and 17% of all outfall and canal samples, respectively. Samples were positive at beaches 8% of the time. These data illustrate the potential public health hazard associated with recreational waters. Using direct PCR, viruses were detected at the outfall but were not found in any beach or canal samples, in part, owing to substances that inhibit PCR. Therefore, conventional cell culture is the most effective means of detecting low levels of infectious enteroviruses in environmental waters, whereas direct RT-PCR is rendered less effective by inhibitory compounds and low equivalent reaction volumes.
• Reynolds, K. A., Pepper, I. L., & Gerba, C. P. (1996). Detection of infectious enteroviruses by an integrated cell culture-PCR procedure.. Applied and environmental microbiology, 62(4), 1424-7. doi:10.1128/aem.62.4.1424-1427.1996
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  Rapid detection of infectious enteroviruses in environmental samples was made possible by utilizing an integrated cell culture-reverse transcriptase PCR approach. By this method, the presence of infectious enterovirus was confirmed within 24 h, compared with > or = 3 days by cell culture alone. The combined methodology eliminated typical problems normally associated with direct reverse transcriptase PCR by increasing the equivalent volume of environmental sample examined and reducing the effects of inhibitory compounds.
• Johnson, D. C., Rose, J. B., Reynolds, K. A., Pepper, I. L., Johnson, D. C., & Gerba, C. P. (1995). Detection of Giardia and Cryptosporidium in marine waters. Water Science and Technology, 31(5-6), 439-442. doi:10.1016/0273-1223(95)00308-a
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  Raw sewage disposal in marine waters is a common practice in many countries. This practice raises health risk concerns of possible transmission of Giardia and Cryptosporidium . Both of these protozoa have been shown to be transmitted by recreational swimming. To date no studies have determined the efficiency of their detection and concentration in marine waters. This study evaluated the efficiency of their detection in tap water and from marine waters in Hawaii with two different filter types. This study compared a polypropylene fiber cartridge filter, DPPPY (1.0 μm nominal porosity) (Cuno, Meriden, CT) which is typically used for parasite detection and the Filterite negatively charged filter (0.45μm) (Filtemp Sales, Inc., Phoenix, AZ). The latter would allow for both viruses and parasites to be concentrated simultaneously. The organisms were removed from the filter by passing the eluent through the filters in the opposite direction of collection and detected by indirect immunofluorescence antibody staining specific for Giardia and Cryptosporidium . Processing was simpler and faster with the Filterite filter and the overall efficiency for both Giardia and Cryptosporidium detection was greater. These methods are currently being used for the detection of the oocysts and cysts at bathing beaches in Hawaii impacted by marine sewage discharge.
• Reynolds, K. A., & Reynolds, K. A. (1995). Detection of enteroviruses in marine waters using RT-PCR.. Water Science and Technology.
• Reynolds, K. A., Pepper, I. L., & Gerba, C. P. (1995). Detection of enteroviruses in marine waters by direct RT-PCR and cell culture. Water Science and Technology, 31(5-6), 323-328. doi:10.1016/0273-1223(95)00288-x
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  Sewage outfalls and storm water runoff introduces pathogenic human enteric viruses into marine coastal waters, which may pose a potential public health risk. Although members of the enterovirus group have been suggested as possible indicators of sewage pollution in marine waters, the lack of rapid, sensitive and cost effective methods have prevented routine monitoring in the United States. This study compared traditional cell culture and direct RT-PCR (reverse transcriptase-polymerase chain reaction) amplification for detection of an enterovirus. Poliovirus could be recovered from 100 L of artificial seawater with an average efficiency of 77%, using adsorption and elution from electronegative filters. Viruses were eluted from the filters with 1.5% beef extract for viruses (BEV) adjusted to pH 9.5 and reconcentrated by organic flocculation to a volume of 30 mL. Substances which interfered with detection by RT-PCR were removed by treatment of the concentrates with sephadex and chelex resins. Direct RT-PCR could detect 2.5 and 0.025 PFU (plaque forming units) for single (25 cycles) and double PCR (2 × 25 cycles) in 10 μL of pure culture poliovirus samples, respectively. These methods are currently being applied to assess the occurrence of enteroviruses at marine bathing beaches influenced by sewage discharges.
• Rose, J. B., Reynolds, K. A., & Giordano, A. T. (1993). Comparison of Methods for the Recovery and Quantitation of Coliphage and Indigenous Bacteriophage from Marine Waters and Sediments. Water Science and Technology, 27(3-4), 115-117. doi:10.2166/wst.1993.0332
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  A variety of anthropogenic influences on marine coastal waters introduces populations of human enteric bacteria and their bacteriophage, some of which may be indicators of municipal waste contamination. This work was undertaken to examine methods for recovery and detection of coliphage in marine waters and sediments. Seeded studies were used to compare viradel and Ultrafiltration methods for the recovery and concentration of both indigenous and introduced viruses from seawater. Ultrafiltration recoveries of MS2 averaged 29.3% in artificial seawater. Viradel methods used to concentrate MD1 coliphage averaged 18.7% recovery when used with natural seawater. A variety of eluants were examined for recovery of phage from sediments. Recoveries ranged from 0.8-100% depending on the type of phage and eluant used. No eluant was capable of providing more efficient recoveries over another, however, indigenous phage #16 was isolated more efficiently than introduced tailed phages T2 and MD1. For phage quantitation, plaque assay counts were compared to particle counts using TEM. TEM counts were usually higher than PFUs in artificial seawater concentrates but lower with eluted marine sediments. Environmental surveys revealed that phage could sometimes be isolated from sediments when they could not be detected in the overlying water column. Preliminary data showed phage could be isolated from sea cucumbers and sponges at higher concentrations than in their surrounding habitats. Therefore, with the development of efficient elution and rapid quantitation techniques, sediments and sea organisms are the most appropriate sampling sites for detection of marine phage populations.

Proceedings Publications

• Reynolds, K. A., Mata-Robles, S., Breshears, L. E., & Yoon, J. (2022). Flow rate profile based PFAS detection on smartphone- and paper-based microfluidics. In 2022 IEEE Research and Applications of Photonics in Defense Conference (RAPID), Miramar Beach, FL, USA, doi:10.1109/RAPID54472.2022.9911269.
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  Sensitive detection of PFOA, type of PFAS (perfluorinated-alkyl substances), was demonstrated on paper-based microfluidic chip utilizing competitive binding with albumin or casein and cellulose fibers. It altered the capillary flow rate profile and monitored by a smartphone camera. Detection limit was 1-10 fg/µL (1-10 ppt).
• Reynolds, K. A., Wilson, A. M., King, M., Lopez-Garcia, M., Clifton, I., Proctor, J., & Noakes, C. J. (2021). Integrating CFD and exposure modeling for estimating viral exposures at the air-surface interface. In AIAA AVIATION Forum and Exposition Conference.
• Yoon, J., Reynolds, K. A., Cho, S., Breshears, L. E., & Chung, S. (2017, Jul.). Rapid and Reliable Norovirus Assay at pg/mL Level Using Smartphone-Based Fluorescence Microscope and a Microfluidic Paper Analytic Device. In ASABE Annual International Meeting, 2017, 1701234.
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  Detection of norovirus from water samples typically requires extremely low limit of detection (LOD), preferably at single virus particle level, since they can be pathogenic at extremely low concentrations. Complicated equipment and/or lengthy procedures are necessary to concentrate large volume of water sample. In addition, this low LOD requirement have traditionally been associated non-reproducible and less convincing assay results. In this work, rapid and reliable detection of norovirus contamination in water samples was demonstrated using an in-house developed smartphone-based fluorescence microscope and a paper microfluidic analytic device (μPAD). Norovirus was concentrated directly on the μPAD, which was fabricated with polarity filter, to further decrease the LOD. Antibody-conjugated submicron (0.5 μm diameter) fluorescent particles were added to this μPAD, and a smartphone based fluorescence microscope imaged these beads directly from the μPAD. Since the spatial resolution of our smartphone-based fluorescence microscope is > 1 μm, only the beads immunoaggltuinated by norovirus can be identified, providing reliable, reproducible, and visually convincing assay results. Using this novel this method, extremely low LOD was demonstrated, 0.01 pg/mL with a benchtop fluorescence microscope and 10 pg/mL to 100 pg/mL with a smartphone based fluorescence microscope. This novel assay can provide a fully unmanned platform for assaying various waterborne pathogens that require extremely low LOD as well as high reliability, while providing low-cost, ease-of-use, and user friendliness appropriate for field applications.
• Yoon, J., Reynolds, K. A., Paz, V., Tat, T., & McCracken, K. E. (2017, Jul.). Immunoagglutinated Particle Rheology Sensing on a Microfluidic Paper-Based Analytical Device for Pathogen Detection. In ASABE Annual International Meeting, 2017, 1701190.
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  Particle immunoagglutination assays have been successfully used in biological sensing for food, water, and environmental applications and medical diagnostics. In this method, interactions between antibody-conjugated particles and biological targets are typically quantified by optical-based sensing, including Mie scattering detection. While these optical methods demonstrate favorable sensitivity and specificity, those that measure light intensity changes are vulnerable to environmental perturbations, such as variations in ambient lighting or humidity. In this work, we investigated a new sensing method based on the particle rheology of immunoagglutinated samples, as seen in droplet spreading on a microfluidic paper-based analytical device (µPAD). By monitoring the overall bulk movement of a particle suspension on paper, these assays are not as critically affected by the sensing environment. Capillary flow of the particle suspension on µPAD channels was tuned by adjusting various parameters, including paper thickness, channel width, channel morphology, particle concentration, and particle size. We then tested the most favorable lateral flow channel design for E. coli K12 sensing in water samples, and applied this overall technique to Zika virus (ZIKV) sensing in biological matrices. From these assays, we achieved similar limits of detection as compared with other demonstrated methods (2 log CFU/mL E. coli; 0.53x10^4 transcription copies/mL). Based on this work, direct detection of immunoagglutinated particle rheology through droplet spreading shows promise as a unique and simple method with applications in automated biosensors for environmental and health samples.
• Sexton, J. D., Lucas, P., Yang, Z., Sexton, J. D., Reynolds, K. A., Lucas, P., & Fah, M. K. (2011). Detection of bio-molecules using conductive chalcogenide glass sensor. In 2011 International Quantum Electronics Conference (IQEC) and Conference on Lasers and Electro-Optics (CLEO) Pacific Rim incorporating the Australasian Conference on Optics, Lasers and Spectroscopy and the Australian Conference on Optical Fibre Technology, 2026-2028.
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  Novel telluride glasses with high electrical conductivity, wide infrared transparency and good resistance to crystallization are used to design an opto-electrophoretic sensor for detection and identification of hazardous microorganisms. The sensor is based on an attenuated total reflectance element made of Ge-As-Te glass that serves as both an optical sensing zone and an electrode for driving the bio-molecules within the evanescent wave of the sensor. An electric field is applied between the optical element and a counter electrode in order to induce the migration of bio-molecules carrying surface charges. The effect of concentration and applied voltage is tested and the migration effect is shown to be reversible upon switching the electric field. The collected signal is of high quality and can be used to identify different bio-molecules through spectral analysis. This technique therefore provides the ability to detect hazardous microorganisms with high specificity and good sensitivity in aqueous environments.
• Kuwahara, S. S., Reynolds, K. A., Kuwahara, S. S., Gerba, C. P., & Cuello, J. L. (2003). Synergistic UV-Ozone Effects on the Treatment of Pathogens in Secondary Effluent. In SAE Technical Paper Series.
• Reynolds, K., Gerba, C., & Pepper, I. (1997). Rapid PCR-based monitoring of infectious enteroviruses in drinking water. In Drinking Water Research, 7, 6.
  More info

  Currently, the standard method for the detection of enteroviruses and hepatitis A virus in water involves cell culture assay which is expensive and time consuming. Direct RT-PCR offers a rapid and sensitive alternative to virus detection but sensivity is often reduced by PCR inhibitory substances and the requirement for small reaction volumes. Rapid methods for detection of infectious enteroviruses in PCR inhibitory environmental samples are being developed utilising an integrated cell culture/PCR approach (ICC/PCR). With this approach, 300-400l of water were concentrated using charged filters followed by a modified 11, 1.5% BEV/glycine elution and organic flocculation reconcentration. Water concentrates were analysed by direct RT-PCR, conventional cell culture and ICC/PCR. For ICC/PCR, sample concentrates were incubated with BGM or FRhK cells for 24-48h. The cell culture lysates were collected following freeze-thaw cycles, centrifuged, resin column purified and PCR amplified. In this study viruses known to be present by cell culture analysis could not be detected by direct PCR. Using the integrated method, virus concentrations as low as 0.001 MPN/l of original water were detected in samples which were previously inhibitory to direct PCR. In addition, confirmed enterovirus results were achieved as soon as 48 h against 5-16 d with cell culture alone. Therefore, the integrated approach overcame some of the traditional problems associated with conventional cell culture and direct RT-PCR by allowing rapid, confirmed detection of low levels of enteroviruses in PCR inhibitory samples. Currently, the standard method for the detection of enteroviruses and hepatitis A virus in water involves cell culture assay which is expensive and time consuming. Direct RT-PCR offers a rapid and sensitive alternative to virus detection but sensitivity is often reduced by PCR inhibitory substances and the requirement for small reaction volumes. Rapid methods for detection of infectious enteroviruses in PCR inhibitory environmental samples are being developed utilising an integrated cell culture/PCR approach (ICC/PCR). With this approach, 300-4001 of water were concentrated using charged filters followed by a modified 11, 1.5% BEV/glycine elution and organic flocculation reconcentration. Water concentrates were analysed by direct RT-PCR, conventional cell culture and ICC/PCR. For ICC/PCR, sample concentrates were incubated with BGM or FRhK cells for 24-48h. The cell culture lysates were collected following freeze-thaw cycles, centrifuged, resin column purified and PCR amplified. In this study viruses known to be present by cell culture analysis could not be detected by direct PCR. Using the integrated method, virus concentrations as low as 0.001MPN/1 of original water were detected in samples which were previously inhibitory to direct PCR. In addition, confirmed enterovirus results were achieved as soon as 48h against 5-16d with cell culture alone. Therefore, the integrated approach overcame some of the traditional problems associated with conventional cell culture and direct RT-PCR by allowing rapid, confirmed detection of low levels of enteroviruses in PCR inhibitory samples.

Presentations

• Ackerley, L., Sexton, J. D., & Reynolds, K. A. (2024, November). Boosting health & wealth: using targeted hygiene to reduce the health economic burden of infections. 17th European Public Health (EPH) Conference. Lisbon, Portugal.
• Krause, C., Stoica, A., & Reynolds, K. A. (2024, September). Training preferences of health departments’ emergency preparedness and epidemiology staff to inform public health workforce development. CityMatCH Leadership & MCH Epidemiology Conference. Seattle, Washington.
• Newman, J., Aluko, P., Upson, S., Buckley, C., Sexton, J. D., Davies, H., Vale, L., & Reynolds, K. A. (2024, November). Health & wealth: Targeted hygiene reduces the health economic burden of workplace infections. 17th European Health Conference. Lisbon, Portugal: Newman, J., S. Malik, P. Aluko, S. Upson, C. Buckley, J. Sexton, H. Davies, L. Vale,.
• Newman, J., Upson, S., Malik, S., Gent, L., Ackerley, L., Buckley, C., Saha, R., Sexton, J. D., Norman, A., & Reynolds, K. A. (2024, November). Shared spaces, shared germs: Breaking the chain of infection with Targeted hygiene. 17th European Health Conference. Lisbon, Portugal: Newman, J., S. Upson, S. Malik, L. Gent, L. Ackerley, C. Buckley, R. Saha*, J. Sexton, A. Norman, K. Reynolds..
• Reynolds, K. A. (2023). Who touched that? Interconnection of high-touch surfaces drives pathogen spread in public spaces. European Public Health Conference. Dublin, Ireland.
• Reynolds, K. A. (2024, March). Introduction to QMRA (Quantitative Microbial Risk Assessment): Tracer Studies, Exposure Assessment, and Modeling. Reckitt Workshop. Montvale, NJ.
• Reynolds, K. A. (2024, March). QMRA (Quantitative Microbial Risk Assessment) Modeling Approaches to Quantify Infection Risks and Inform Policy Decisions. Reckitt International Medical Science Academy. Reckitt International Medical Science Academy. Hull, UK.
• Reynolds, K. A. (2024, November). Building Effective Infection Control for EMS/Fire: A MRSA Case Study Intervention. South Korean National Fire Agency Seminar. Tucson, AZ.
• Reynolds, K. A., & Peterson, E. H. (2024, November). From Research to Reality: Communicating Science Effectively in Public Health. Enhancing Presentation Skills, Storytelling, and Cultural Competence  . WRPHTC Future Leaders Program Webinar. US Region 9 Online.
• Reynolds, K. A., & Yoon, J. (2024, February). Smartphone and paper-based microfluidic devices for detection of PFAS waterborne contaminants. Water & Environmental Technology (WET) Center Semi-annual Meeting. Arizona State University, Tempe, AZ.
• Reynolds, K. A., Sexton, J. D., & Jung, Y. (2024, November). Desk-sharing in workplaces: Economic analysis of targeted hygiene intervention (THI) in reducing risk of common infections. International Health Economics Conference. United Kingdom.
• Reynolds, K. A., Sexton, J. D., Norman, A., & Ackerley, L. (2024, November). Shared spaces, shared germs: breaking the chain of infection with smart hygiene . 17th European Public Health (EPH) Conference. Lisbon, Portugal.
• Wilson, A. M., Pham, N., Spicka, P., Fryd, M. M., Haas, M. S., Falbo, D. M., Jiang, H., Ashraf, A., & Reynolds, K. A. (2024, December). Computational fluid dynamics and QMRA (Quantitative Microbial Risk Assessment) modelling of influenza A virus and rhinovirus transmission in a shared children’s bedroom. Society for Risk Analysis (SRA) Annual Meeting. Austin, TX: Wilson, A.M., N. Pham, P. Spicka, M.M. Fryd, M.S. Haas, D.M. Falbo, H. Jiang, A. Ashraf, K.A. Reynolds..
• Reynolds, K. A. (2023). Cleaning smarter, not harder: Tracking the journey of the germ and quantifying targeted hygiene impacts in public spaces. ASM Microbe. Houston, TX.
• Reynolds, K. A. (2023). Using Targeted Hygiene to disrupt the journey of the germ and reduce risk of infection. 15th Annual Conference on Infection Prevention (IP2023). Liverpool, England.
• Reynolds, K. A. (2023). Targeted Hygiene reduces surface transmission and infection risk for respiratory viruses. European Public Health Conference. Dublin, Ireland.
• Reynolds, K. A. (2023, July). Journey of the Germ- and the Germologist. UBRP. Tucson, AZ: UBRP.
• Reynolds, K. A. (2023, September). WRPHTC and ESRAC Centers Overview. Feast your brain. Tucson, AZ: MEZCOPH.
• Varyvoda, Y., Reynolds, K. A., & Von Hippel, F. A. (2023). The One Health Occupational Outlook. 2nd International One Health Conference.
• Varyvoda, Y., Reynolds, K. A., & Von Hippel, F. A. (2023, October). The One Health Occupational Outlook. 2nd International One Health Conference. Barcelona, Spain.
• Reynolds, K. A. (2021, July). Risk Communication and Building Public Trust. Water Quality Association (WQA) Convention & Exposition. Las Vegas, NV: WQA.
• Reynolds, K. A. (2022, August). Utilizing Quantitative Microbial Risk Assessment (QMRA) Modelling to Quantify Fomite Roles in Disease Transmission: Estimating Targeted Risk Thresholds. . Virtual Workshop on the Role of Fomites in the Spread of Viruses in the Built Environment. Tucson, AZ.
• Reynolds, K. A. (2022, January). Evaluating Hygiene Intervention Impacts on Infectious Disease Transmission: Utilizing Microbial Tracers and QMRA Modelling to Quantify Mitigation Effects and Estimate Human Health Outcomes. Reckitt Professional Seminar. Online International Forum.
• Reynolds, K. A. (2022, January). Smartphone and paper-based microfluidic devices for detection of PFAS and waterborne contaminants. Water & Environmental Technology (WET) Center Semi-annual Meeting. Tucson, AZ: NSF-WET Center.
• Reynolds, K. A. (2022, January). Research progress toward health improvements for fire fighters. Tucson Fallen Fire Fighters Memorial. Tucson, AZ.
• Reynolds, K. A. (2022, November). Application of QMRA in Assessing Pathogen Risks from Fomites. Workshop on the Role of Fomites in the Spread of Viruses in the Built Environment. Atlanta, GA: Reckitt/CDC.
• Reynolds, K. A. (2022, November). Perspectives for Arizona-France Research Cooperation on Health and Environmental Change. Panelist. Health and Environmental Change: Pushing Research Boundaries through Arizona-France Cooperation. Tucson, AZ: iGlobes Interdisciplinary and Global Environmental Studies.
• Reynolds, K. A. (2022, November). How Do You Solve a Problem Like Germs?. ADHS Sanitarian Conference. Online: Arizona Department of Health Services.
• Reynolds, K. A. (2022, September). Discussion Panelist. One Health Fall Symposium. Tucson, AZ.
• Breshears, L. E., Mata Robles, S., Reynolds, K. A., & Yoon, J. (2021, Aug.). Flow rate profile based PFOA detection on paper-based microfluidics using competitive interactions with albumin and nitrocellulose. ACS Fall 2021 National Meeting & Exposition. Atlanta, GA: American Chemical Society (ACS).
• Gerba, C. P., Reynolds, K. A., Pearce-Walker, J., & Verhougstraete, M. (2018, May). Cost benefits of point-of-use devices to reduce waterborne diseases. University of North Carolina Water Microbiology conference. Chapel Hill, NC.
• Reynolds, K. A. (2014, August). Trends in Environmental Hygiene: Preventing and Controlling Infections. Arizona Health Care Association’s Annual Conference & Trade Show. Scottsdale, AZ.
• Reynolds, K. A. (2014, October). Comparison of Chemical and Microbial Contaminants in Tap, Bottled and Vended Water in a U.S.-Mexico Border Community. International Society of Exposure Science (ISES).
• Reynolds, K. A. (2021, April). Use of a Germicidal Ultraviolet (UVC) Light on Porous and Non-porous Textiles to Reduce Staphylococcus aureus and Escherichia coli Contamination in Emergency Medical Services (EMS) Vehicles. American Society of Safety Professionals (ASSP)- American Industrial Hygiene Association (AIHA) Joint Conference. Online.
• Reynolds, K. A. (2021, August). Flow rate profile based PFOA detection on paper-based microfluidics using competitive interactions with albumin and nitrocellulose. American Chemical Society (ACS). Atlanta, GA.
• Reynolds, K. A. (2021, August). Integrating CFD and exposure modeling for estimating viral exposures at the air-surface interface. AIAA AVIATION Forum and Exposition Conference Proceedings. Online.
• Reynolds, K. A. (2021, February). Infectious disease quantitative assessment: risk of infection through fomite-mediated transmission in a restroom. ENVS Departmental Conference: Envision. UA ENVS.
• Reynolds, K. A. (2021, January). How Clean is Clean? Environmental Risks of HAIs. Munich RE Specialty Insurance Healthcare Risk Management Webinar. Online: Munich RE.
• Reynolds, K. A. (2021, June). Continuously Active Disinfectants: Addressing Challenges of Surface Contamination. TIPS Master Class. Online: Infection Control Tips.
• Reynolds, K. A. (2021, June). Evaluating Hygiene Intervention Impacts on COVID-19 Infections. Universidad Popular Autonoma del Estado de Puebla (UPAEP). Online: UPAEP-MEZCOPH GHI.
• Reynolds, K. A. (2021, June). Home Hygiene: Keeping Your Home Clean, Safe, and Healthy. UAHS Wellness Wednesdays. Online: UAHS.
• Reynolds, K. A. (2021, March). Estimating V. parahaemolyticus illness risk from Pacific oysters harvested in Southern California using a quantitative microbial risk assessment framework. MEZCOPH Public Health Poster Forum. Tucson, AZ.
• Reynolds, K. A. (2021, May). Hospitality Re-Entry: Hygiene and Human Health: Utilizing Microbial Tracers and QMRA Modelling to Quantify Infection Risks and Intervention Impacts. RESTRUCT SymposiumUA RII.
• Reynolds, K. A. (2021, November). Sanitary sewer overflows in Ambos Nacos- a quantitative microbial risk assessment at Naco elementary. American Society of Agronomy; Crop Science Society of America and Soil Science Society of America conference. ASA, CSSA & SSSA International Annual Meeting. Online.
• Reynolds, K. A. (2021, October). Continuously Active Disinfectants: Addressing Challenges of Surface Contamination and Biofilm Growth. Cleaning, Disinfection and Sterilization Conference, Association for Professionals in Infection Control and Epidemiology. Online: APIC.
• Reynolds, K. A. (2021, September). Infection Control and Risks: SARS-CoV-2 and other Virus Expertise at UArizona. UArizona Researcher Highlights and City Projects. Online: RII.
• Reynolds, K. A., & Wilson, A. M. (2020, sept). Characterizing hand-to-face contact frequency and sequence for adults. International Society of Exposure Science (ISES). 2020 Annual Meeting. online.
• Reynolds, K. A. (2020, apr). COVID-19 Workplace Prevention. YWCA Southern Arizona Small Businesses. Zoom Webinar. Zoom; Facebook: YWCA Southern Arizona.
• Reynolds, K. A. (2020, jan). Smartphone Water Quality Monitoring Field Demonstration. AZ Water Research Symposium. Phoenix, AZ: Gateway Community College.
• Reynolds, K. A. (2020, mar). Video to Guide EMS Exposure Reduction. Sustaining Emergency Medical Services during COVID-19Joint Public Safety Sector (PSS) Council and Healthcare and Social Assistance (HCSA), NORA Council Meeting..
• Reynolds, K. A. (2020, may). COVID-19 Occupational Assessment and Transmission Prevention. MEZCOPH Community Advisory Board. Zoom: MEZCOPJ.
• Reynolds, K. A. (2020, sept). Getting Down and Dirty with Environmental Health Concerns.. Keeping Up With Public Health podcast.. podcast: Western Region Public Health Training Center.
• Reynolds, K. A., & Wilson, A. M. (2020, Nov). Defining “clean” in indoor environments with a QMRA risk-based approach: The need for multi-route exposure assessment. Indoor Air. online.
• Reynolds, K. A., & Wilson, A. M. (2020, aug). QMRA modelling to predict shower exposures to Legionella. NSF Legionella Conference. online.
• Reynolds, K. A., & Wilson, A. M. (2020, mar). Estimating the contribution of a contaminated wheelchair to pathogen spread with an agent-based model. The Society for Healthcare Epidemiology of America’s (SHEA) 6th Decennial International Conference on Healthcare Associated Infections. Atlanta, GA.
• Reynolds, K. A., & Wilson, A. M. (2020, nov). . Defining “clean” in indoor environments with a QMRA risk-based approach: The need for multi-route exposure assessment. Indoor Air Conference. virtual online.
• Reynolds, K. A., & Wilson, A. M. (2020, nov). Modelling the influence of room orientation and care type on differences in norovirus exposure via an air-surface interface transmission route. Indoor Air Conference. virtual conference.
• Reynolds, K. A., Gerba, C. P., Ramirez, M. D., & Morales, A. a. (2020, nov). Sanitary sewer overflows in Ambos Nacos- a quantitative microbial risk assessment at Naco elementary. American Society of Agronomy; Crop Science Society of America and Soil Science Society of America conference. ASA, CSSA & SSSA International Annual Meeting. Virtual online: ASA, CSSA & SSSA.
• Gerba, C. P., Reynolds, K. A., Gerald, J. K., & Verhougstraete, M. (2019, June). Cost-Benefit of Point of Use Devices for Lead Reductions. American Water Works Association ACE 2019. Denver, CO: WQRF.
• Klug, K. E., Reynolds, K. A., & Yoon, J. (2019, Aug.). Capillary Flow Dynamics-Based Sensing Modality for Direct Environmental Pathogen Monitoring. ACS National Meeting & Expo. San Diego, CA: ACS.
• Yoon, J., Reynolds, K. A., Betancourt, W. Q., Morrison, C. M., Perea, S., Breshears, L. E., & Chung, S. (2019, Aug.). Smartphone-Based Paper Microfluidic Particulometry of Norovirus from Environmental Water Samples at Single Copy Level. ACS National Meeting & Expo. San Diego, CA: ACS.
• Chung, S., Breshears, L. E., Morrison, C. M., Betancourt, W. Q., Reynolds, K. A., & Yoon, J. (2018, May). Single Particle Level Norovirus Detection Assay Using Smartphone-Based Fluorescence Microscope and a Microfluidic Paper Analytic Device. 2nd KU-UA Joint International Symposium. Seoul, South Korea: Korea University.
• Chung, S., Breshears, L. E., Reynolds, K. A., & Yoon, J. (2018, Jan.). Rapid and Reliable Norovirus Assay Using Smartphone-Based Fluorescence Microscope and a Microfluidic Paper Analytic Device. 1st KU-UA Joint International Symposium. Tucson, AZ: University of Arizona.
• Wilson, A. M., Reynolds, K. A., & Canales, R. A. (2018, April). Using Simulation Modeling to Estimate the Effect of Human Behaviors and Cleaning Interventions on Infection Risk. American Society of Safety Engineers Luncheon. Tucson, AZ: American Society of Safety Engineers.
• Wilson, A. M., Reynolds, K. A., & Canales, R. A. (2018, Februrary). Stochastic Discrete Event Modeling to Predict Effects of Surface Cleanings on Viral Infection Risk. Emerging Researchers National Conference in STEM. Washington, DC: National Science Foundation.
• Reynolds, K. A. (2017, April). Waterborne Threats in the U.S.: Understanding the Impact of Persistent and Emerging Contaminants. Culligan Dealers Association of North America, Inc. (CDNA) Convention and Product Fair. St. Louis, MO: Culligan Dealers Association of North America, Inc. (CDNA).
• Reynolds, K. A. (2017, Mar). Santa Clarita Water Softener Ban and Agricultural Impacts. Water Quality Association Convention and Exposition. Orlando, FL: Water Quality Association.
• Reynolds, K. A. (2017, March). Santa Clarita Water Softener Ban and Agricultural Impacts. Water Quality Association Convention and Exposition. Orlando, FL: Water Quality Association.
• Reynolds, K. A. (2017, Nov). Valuation of Intervention Impacts in Healthcare using the Evidence Based Science of Quantitative Risk Assessment Modeling. Environment Hygiene Interest Group (EHIG) for Infection Prevention and Control Canada (IPAC). Webinar: Infection Prevention and Control Canada (IPAC).
• Reynolds, K. A. (2017, Oct). Review of the Risk, Communication and Perception of the Santa Clarita Valley Water Softener Ban. Pacific Water Quality Association Annual Meeting (PWQA). Newport Beach, CA: PWQA.
• Reynolds, K. A. (2017, Sept). Surface Decontamination: Challenges and Perspectives. Healthcare Infection Transmission Consortium. Ann Arbor, MI.
• Reynolds, K. A., & Greene, C. (2017, Sept). Catalyst for Change: Overview of the Healthcare Infection Transmission Systems (HITS) Consortium. Healthcare Infection Transmission Systems (HITS) Consortium. Ann Arbor, MI.
• Reynolds, K. A., & Yoon, J. Y. (2017, Dec). Monitoring Water Safety using Smartphone Detection from Paper Microfluidics.. NSF and the Water, Environment and Technology Center Annual Meeting. Tucson, AZ: NSF/WET.
• Reynolds, K. A., Canales, R. A., & Wilson, A. (2017, Oct). Modeling Viral Pathogen Exposure and Risk Reductions for Infection Control Interventions. Lewis Stokes Midwest Center of Excellence (LSMCE) Conference. Indianapolis, IN: Lewis Stokes Midwest Center of Excellence (LSMCE).
• Reynolds, K. A., Gerba, C. P., Sexton, J. D., Humphrey, K., & Leslie, R. (2017, June). Effects of Disinfection on the Spread of Virus in an Outpatient Clinic. Association for Professionals in Infection Control. Portland, OR.
• Reynolds, K. A., Reynolds, K. A., Canales, R. A., Canales, R. A., Gerba, C. P., Gerba, C. P., Sexton, J., & Sexton, J. (2017, June). Understanding the Relationships among HAI, Healthcare Surfaces, and Environmental Interventions using QMRA. 44th Annual Educational Conference of the Association for Professionals in Infection Control. Portland, OR.
• Reynolds, K. A., Sexton, J. D., Scanlon, M. M., & Lee, V. (2017, June). Legionellosis Prevention and Response Training for Environmental Health Professionals. 44th Annual Educational Conference of the Association for Professionals in Infection Control. Portland, OR.
• Wilson, A., Reynolds, K. A., & Canales, R. A. (2017, Oct). Modeling Viral Pathogen Exposure and Risk Reductions for Infection Control Interventions. Louis Stokes Midwest Center of Excellence (LSMCE) Conference. Indianapolis, IN: Lewis Stokes Midwest Center of Excellence (LSMCE).
• Canales, R. A., Littau, S. R., & Reynolds, K. A. (2016, June). Breakfast Symposium: Quantitative risk modeling of healthcare acquired infections and interventions using baseline data and simple models. Association for Professionals in Infection Control Conference. Charlotte, North Carolina.
• Canales, R. A., Littau, S. R., & Reynolds, K. A. (2016, June). Quantitative risk modeling of healthcare acquired infections and interventions using baseline data and simple models. Association for Professionals in Infection Control Conference. Charlotte, North Carolina.
• Reynolds, K. A. (2016, April). Water and Your Health. The Third Annual Environmental Science and Health Youth Conference. Tucson, AZ.
• Reynolds, K. A. (2016, April). Waterborne Pathogens: Emerging Issues in Monitoring, Treatment and Control.. Multipure Annual Conference and Exposition. Henderson, NV: Multipure.
• Reynolds, K. A. (2016, December). Norovirus Detection Using Fluorescence Microscopy. Water, Environment and Technology Center Annual Meeting. Tempe, AZ: NSF/WET.
• Reynolds, K. A. (2016, February). How to Work with PR and the Media. Mel & Enid Zuckerman College of Public Health Faculty Development Meeting. Tucson, AZ: MEZCOPH.
• Reynolds, K. A. (2016, January). Smartphone App and Risk Assessment Model Development.. Arizona Water Research Workshop. Tempe, AZ: Tucson Water.
• Reynolds, K. A. (2016, June). Optimal strategies for monitoring irrigation water quality and the development of guidelines for the irrigation of food crops. The Water Microbiology Conference 2016. Chapel Hill, NC: The Water Institute at the University of North Carolina.
• Reynolds, K. A. (2016, November). Smartphone for Water Quality: Smartphone Detection from Paper Microfluidics for Monitoring Water Safety.. Arizona Water Conference. Phoenix, AZ: Tucson Water.
• Reynolds, K. A. (2016, October). The dynamics of microbe spread via hands and fomites throughout an outpatient clinic. ID Week. New Orleans, LA: ID Week.
• Reynolds, K. A. (2016, October). Water Threats: Known and Unknown. PHSI Dealer Meeting. Las Vegas, NV: PHSI.
• Reynolds, K. A. (2016, Septembere). Quantifying the Impact of Environmental Services in Infection Prevention: Use of Risk Assessment Modeling Tools to Evaluate Interventions in Infection Control. Association for the Healthcare Environment (AHE) Exchange 2016. Pittsburgh, PA: AHE.
• Reynolds, K. A. (2015, April). Boil Water Notices in the U.S., 2012-2014. WQA Research Updates. Las Vegas, NV.
• Reynolds, K. A. (2015, December). Germ Geography: Understanding Public Infection Spread. GOJO/Essendant Conference. San Diego, CA.
• Reynolds, K. A. (2015, December). Smartphone for Water Quality: Smartphone Detection from Paper Microfluidics for Monitoring Water Safety. Water and Environmental Technology Center/ National Science Foundation industry/University Cooperative Research Center Annual Meeting.
• Reynolds, K. A. (2015, July). Microbiology of the Built Environment series. Fourth conference of the Microbiology of the Built Environment series. Boulder, CO.
• Reynolds, K. A. (2015, June). Rapid Microbial Tracer Movement to Soft Surfaces in Patient Care Areas and the Role of Mixed Surfaces in Infection Prevention. APIC 2015 Annual Conference. Nashville, TN.
• Reynolds, K. A. (2015, March). . Fluoride Risk Assessment/Endetec Monitoring of Coliform Bacteria in Water/ Smartphone Microfluidic Water Quality Monitoring. Tucson Water/University of Arizona Project Updates. Citizen’s Water Advisory Committee. Technical /Planning and Policy Subcommittee. Tucson, AZ.
• Reynolds, K. A. (2015, March). Can You Risk It? (Use of Tools in Quantitative Risk Assessment to Evaluate Food Safety Challenges and Solutions). Desert Produce Safety Collaborative Conference. Yuma, AZ.
• Reynolds, K. A. (2015, March). Risky Behaviors. (How Personal Perceptions Drive Fears and Behaviors). Desert Produce Safety Collaborative Conference. Yuma, AZ.
• Reynolds, K. A. (2015, March). Waterborne Pathogen Monitoring. Environmental Health Sciences Seminar Series.
• Reynolds, K. A. (2015, September). Environmental Hygiene: Ebola and Other Emerging Pathogens in Healthcare. Centers for Disease Control and Prevention Headquarters. Atlanta, GA.
• Reynolds, K. A. (2015, September). Evaluation and Control of Infectious Microbes in Healthcare Environments: New Evidence for Best Practices. AHE Exchange 2015. Grapevine, TX.
• Reynolds, K. A. (2015, September). Point-Of-Use Water Treatment Cost-Effectiveness Analysis. Water Quality Association Mid-year Meeting. Tucson, AZ.
• Reynolds, K. A. (2015, September). WQA Research Final Report: Boil Water Notices in the U.S., 2012-2014. Water Quality Association Mid-Year Meeting. Tucson, AZ.
• Reynolds, K. A. (2014, April). HAI Prevention and Control: Soft Surface Decontamination. Medical World Americas Conference. Houston, TX.
• Reynolds, K. A. (2014, June). Case Studies in Environmental Risk Assessment: Successful translation from the field to public health practice. 3rd Annual Sloan Foundation Meeting on Microbiology of the Built Environment. Boulder, CO.
  More info

  Plenary
• Reynolds, K. A. (2014, March). Living with germs. Dean's Circle of Excellence. Tucson, AZ.
• Reynolds, K. A. (2014, March). New Trends in Environmental Hygiene: Decontaminating Soft Surfaces. Infection Control Today (ICT) Webinar. Online.
• Reynolds, K. A. (2014, October). Morning session moderator- speakers’ panel discussion. . 5th Annual Food Safety Conference: Food Safety and One Health. Tucson, AZ.
• Reynolds, K. A. (2014, October). The sexy side of risk assessment. 5th Annual Food Safety Conference: Food Safety and One Health. Tucson, AZ.
• Reynolds, K. A. (2014, October). Waterborne pathogens: Emerging issues in monitoring, treatment, and control. Maricopa County Waterborne Disease Taskforce. Phoenix, AZ.
• Reynolds, K. A. (2014, September). Soft surface infection prevention. McKesson Webinar Wednesdays. Online.
• Reynolds, K. A. (2014, Spring). Infection Control Today Q &A on Environmental Contamination. Infection Control Today Webinar. Online.
• Reynolds, K. A. (2014, Spring). Long-Term Care Facility Infections. Long Term Living. Podcast.
• Reynolds, K. A. (2014, Spring). New Trends in Environmental Hygiene: Decontaminating Soft Surfaces. Association for the Healthcare Environment (AHE) Webinar. Online.
  More info

  CE credits
• Reynolds, K. A., & Sassi, H. (2014, May). Evaluation of a Hygiene Intervention in a Long-term Care Facility. 114th General Meeting of the American Society for Microbiology.
• Reynolds, K. A., & Sexton, J. D. (2014, May). Use of Microbial Surrogates to Evaluate Infection Control Procedures in the Healthcare Environment. 114th General Meeting of the American Society for Microbiology. Boston, MA.
• Victory, K., Cabrera, N. L., Larson, D., Latura, J., Reynolds, K. A., & Beamer, P. (2014, March). Risk and risk perceptions related to drinking bottled water. Risk, Perception and Response Conference. Boston, MA: Harvard University.
• Pleasant, A., Cabe, J., Pereira-Leon, M., & Reynolds, K. A. (2013, November). Evaluating what? Marrying Multiple Methods and Multiple Data Types and Sources: Evaluation of the Arts for Behavior Change Program in Lima, Peru. American Public Health Association. Boston, MA.
• Reynolds, K. A. (2013, Winter). Decontaminating Textiles and Other Soft Surfaces: Evidence-Based Recommendations. Association for the Healthcare Environment (AHE) Exchange 2013 Conference. Indianapolis, IN: Association for the Healthcare Environment (AHE).
• Reynolds, K. A., & Yoon, J. -. (2013, December). Use of Paper Microfluidics and Smartphone Mie Scattering Sensors for Water Quality Monitoring. NSF Water and Environmental Technology Center Industrial Advisory Board Annual MeetingNational Science Foundation.
• Reynolds, K. A., Suppes, L. M., Ernst, K. C., & Gerba, C. P. (2014, Spring). Aquatic Environmental Exposure and Operation Questionnaire Standardization and Validation. 5th International Conference Swimming Pool and Spa. Rome, Italy: National Swimming Pool Foundation (NSPF).
• Suppes, L. M., & Reynolds, K. A. (2013, Spring). Development and Evaluation of a Swimming Pool Exposure Assessment Tool. Arizona County Directors of Environmental Health Services Association/ Southwest Environmental Health Conference. Laughlin, NV: National Swimming Pool Foundation (NSPF).
• Suppes, L. M., Reynolds, K. A., Ernst, K. C., & Gerba, C. P. (2013, January). Influence of Swimmer Activity and Behavior on Pool Water Ingestion. Arizona County Directors of Environmental Health Services Association. Laughlin, NV.

Poster Presentations

• Reynolds, K. A. (2023). Assessing Impacts of Lobby Cleaning and Disinfection on Infection Risks for Hotel Guests. ASM Microbe. Houston, TX.
• Reynolds, K. A. (2023). How much infection risk could surface cleaning reduce for hotel lobby users?. Public Health Poster Forum. Tucson, AZ.
• Reynolds, K. A. (2022, June). What Risks Does the Residential Laundry Process Pose?: A Quantitative Microbial Risk Assessment (QMRA) Study. APIC 2022 Annual Conference. Indianapolis, IN.
• Reynolds, K. A. (2014, June). Occurrence and Control Occurrence and Control of Pathogens on Soft Surfaces in the Healthcare Environment. Association for Professionals in Infection Control and Epidemiology. Anaheim, CA.
• Reynolds, K. A., & Sexton, J. D. (2013, Winter). Occurrence and Control Occurrence and Control of Pathogens on Soft Surfaces in the Healthcare Environment. Association for Professionals in Infection Control and Epidemiology (APIC). Anaheim, CA: Clorox Co..
• Reynolds, K. A., Sinclair, R. G., Soto-Beltran, M., & Canales, R. A. (2014, October). Simulating Non-Dietary Ingestion of Listeria monocytogenes in Residential Environments. International Society of Exposure Science (ISES). Cincinnati, OH.
• Sifuentes, L. Y., Sassi, H. P., Reynolds, K. A., Clark-Greuel, J., Nichols, E., McGrath, K., & Koenig, D. W. (2013, Spring). Impact of a Hygiene Intervention on Virus Transmission in a Long Term Care Facility. Association for Professionals in Infection Control and Epidemiology (APIC). Anaheim, CA.
• Reynolds, K. A., & Wilson, A. M. (2020, Spring). Characterizing frequency and sequence of adults’ and children’s hand-to-head, -mouth, -eyes, and -nose contacts. Discover BIO5 Research to Innovation Showcase. Tucson, AZ.
• Reynolds, K. A., & Wilson, A. M. (2020, jun). Comparing contaminant transfer potential of repetitive hand-to-fomite contacts for gloved and ungloved hands using a fluorescent powder. APIC. online.
• Reynolds, K. A., & Wilson, A. M. (2020, sept). COVID-19 Infection Risk: Are there differences between eating and non-eating behaviors?. International Society of Exposure Science (ISES). 2020 Annual Meeting. online.
• Reynolds, K. A., Garavito, F., & Sexton, J. D. (2020, Jun). Whole-room hypochlorous acid atomizing disinfection system on healthcare surface contamination and transfer. Poster Presentation. APIC. online.
• Reynolds, K. A., Lugo, V., & Wilson, A. m. (2020, June). Evaluating the use of ultraviolet light to reduce transmission of methicillin-resistant Staphylococcus aureus in emergency medical service vehicles. APIC. online.
• Wilson, A. M., Canales, R. A., Gerba, C. P., & Reynolds, K. A. (2018, April). How Much Are Surfaces to Blame in Norovirus Outbreaks?. Mel & Enid Zuckerman College of Public Health Research Forum. Tucson, AZ: Mel & Enid Zuckerman College of Public Health.
• Wilson, A. M., Reynolds, K. A., & Canales, R. A. (2018, March). Validation of a Stochastic Discrete Event Model for Predicting Viral Pathogen Exposure. Western Alliance to Expand Student Opportunities Conference. Arizona State University, Phoenix, AZ: Western Alliance to Expand Student Opportunities.
• Wilson, A. M., Reynolds, K. A., Robert, C. A., Wilson, A. M., Reynolds, K. A., & Robert, C. A. (2018, June). Predicting Viral Infection Risks and Optimizing Hygiene Protocols Using a Modeling Approach. Association for Professionals in Infection Control and Epidemiology Annual Conference. Minneapolis, MN: Association for Professionals in Infection Control and Epidemiology.
• Reynolds, K. A., Sexton, J., & Reynolds, A. (2017, April). Quantitative Characterization of Microbial Malodor in Laundry. MEZCOPH Student Poster Forum. Tucson, AZ.
• Reynolds, K. A., Sexton, J., Sassi, H., & Wilson, A. (2017, April). Microbial Transfer from Soft Surfaces and its Control in Healthcare Settings. MEZCOPH Student Poster Forum. Tucson, AZ.
• Reynolds, K. A., Troup, D., Verhougstraete, M., & Sexton, J. (2017, April). Bioaerosol Reduction with a Passive Air Treatment System in a Controlled Chamber. MEZCOPH Student Poster Forum. Tucson, AZ.
• Reynolds, K. A. (2016, December). Viruses as New Indicators of Human and Cattle Fecal Contamination of Irrigation Water. Water and Energy Sustainable Technology Center. Tucson, AZ: WEST Center.
• Ornelas, Y., Reynolds, K. A., Abrell, L. M., Grigera, S., & Beamer, P. (2014, October). Microbial and inorganic contamination in private wells along the Santa Cruz River, Arizona. International Society of Exposure Science. Cincinnati, OH.
• Reynolds, K. A. (2014, June). Impact of a Hygiene Intervention on Virus Transmission in a Long Term Care Facility. Association for Professionals in Infection Control and Epidemiology. Anaheim, CA.
• Victory, K., Cabrera, N. L., Larson, D., Reynolds, K. A., Latura, J., & Beamer, P. (2014, March). Risk perception of drinking water quality and in a US-Mexico Border community. Risk, Perception, and Response Conference. Harvard Center for Risk Analysis. Boston, MA.
• Victory, K., Reynolds, K. A., Cabrera, N. L., Larson, D., Burgess, J. L., & Beamer, P. (2014, April). Comparison of Chemical and Microbial Contaminants in Tap, Bottled and Vended Water in a U.S.-Mexico Border Community. UA Poster Forum. Tucson, AZ.
• Victory, K., Reynolds, K. A., Cabrera, N. L., Larson, D., Latura, J., Burgess, J. L., & Beamer, P. I. (2014, October). Comparison of CHemical and Microbial Contaminants in tap, Bottled, and Vended Water in a U.S.-Mexico Border Community. International Society of Exposure Science. Cincinnati, OH.
• Canales, R. A., & Reynolds, K. A. (2013, December). Simulating Non-Dietary Ingestion of Listeria monocytogenes from Residential Surfaces. Society for Risk Analysis Conference. Baltimore, MD: Society for Risk Analysis.
• Reynolds, K. A., & Sexton, J. D. (2013, October). Evaluation of a Soft Surface Sanitizer in Healthcare Environments. IDWeek 2013. San Francisco, CA.
• Reynolds, K. A., & Supes, L. M. (2013, May). Swimming Pool Water Ingestion Exposure Assessment using Videography and Exposure Questionnaires. 113th General Meeting of the American Society for Microbiology. Denver, CO.
• Reynolds, K. A., Sexton, J. D., & Valdez, M. K. (2013, May). Transfer and Control of Microbes in Emergency Vehicles. 113th General Meeting of the American Society for Microbiology. Denver, CO.
• Reynolds, K. A., Valdez, M. K., & Sexton, J. D. (2013, March). Transfer and control of infectious microbes in fire apparatuses. SEHSA. Public Health Research Poster Forum. Tucson, AZ.
• Sexton, J. D., Valdez, M. K., & Reynolds, K. A. (2013, March). Occurrence of methicillin resistant Staphylococcus aureus (MRSA) in fire stations. Student Environmental Health Science Association/ Public Health Research Poster Forum. Tucson, AZ.
• Valdez, M. K., Sexton, J. D., & Reynolds, K. A. (2013, May). Occurrence of methicillin resistant Staphylococcus aureus (MRSA) in fire stations. 113th General Meeting of the American Society for Microbiology. Denver, CO.
• Victory, K., Cabrera, N. L., Larson, D., Latura, J., Reynolds, K. A., & Beamer, P. -. (2013, December). Risk Perception of Drinking Water Quality in a U.S.-Mexico Border Community. Society for Risk Analysis Annual Conference. Baltimore, MD.
• Victory, K., Larson, D., Cabrera, N. L., Reynolds, K. A., & Beamer, P. -. (2013, March). Risk perception, drinking water source quality in a low-income Latino community along the US-Mexico Border. SEHSA. Public Health Research Poster Forum. Tucson, AZ.

Reviews

• Reynolds, K. A. (2021. Developing and promoting hygiene in home and everyday life to meet 21st Century needs. What can we learn from the COVID-19 pandemic?.
• Reynolds, K. A. (2015. Celebration of the Safe Drinking Water Act’s 40th Anniversary and Recognition of the Challenges Ahead.
• Reynolds, K. A. (2015. Deadly Legionella: Commonly Found in U.S. Water Systems.
• Reynolds, K. A. (2015. Drinking Water Disinfection: Options and Hazard Management.
• Reynolds, K. A. (2015. Graywater: Reuse and Risks Revisited.
• Reynolds, K. A. (2015. Human Perception is a Failed Indicator of Water Quality Concern.
• Reynolds, K. A. (2015. Industrial Waste Risk and Management in Drinking Water Sources.
• Reynolds, K. A. (2015. Methadone Creates Harmful Byproducts in Treated Drinking Water.
• Reynolds, K. A. (2015. New Tools for Assessing Groundwater Risks.
• Reynolds, K. A. (2015. POU Prevention of Healthcare Acquired Waterborne Infections.
• Reynolds, K. A. (2015. POU Water Filtration Saving Lives in California.
• Reynolds, K. A. (2015. Warmer Waters Heighten Toxic Algae Production.
• Reynolds, K. A. (2015. Why a POU device?.

Others

• Reynolds, K. A. (2016, November). Boil Water Notices in the United States- 2012-2014. Water Quality Association Research Foundation..
• Verhougstraete, M., Gerba, C. P., & Reynolds, K. A. (2016, September). Cost benefit of point-of-use devices in reduction of health risks from drinking water..
  More info

  Verhougstraete, M.P., K., Reynolds, A. Tamimi, and C. Gerba. 2016. Cost benefit of point-of-use devices in reduction of health risks from drinking water. A technical report For Water Quality Research Foundation.