Marc Verhougstraete

Interests

Research

Water quality microbiologyEnvironmental microbiologyAgriculture and food safetyIrrigation water qualityDrinking water and climate change connectionsQuantitative Microbial Risk Assessment (QMRA)

Courses

Scholarly Contributions

Books

• 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

• 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.

Journals/Publications

• Verhougstraete, M. P., Ruiz, J. M., Pearce-walker, J., Mcclelland, J., & Hermanski, A. (2021). The effects of blue spaces on mental health and associated biomarkers. International Journal of Mental Health, 1-15. doi:10.1080/00207411.2021.1910173
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  Green spaces have been shown to have many benefits for physical and mental health. Recently, blue spaces have been introduced as another field of research and have been suggested to have similar he...
• Verhougstraete, M. P., Wilson, A. M., Verhougstraete, M. P., Reynolds, K. A., & Donskey, C. J. (2021). An agent-based modeling approach to estimate pathogen exposure risks from wheelchairs.. American journal of infection control, 49(2), 206-214. doi:10.1016/j.ajic.2020.06.204
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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..An agent-based model was informed by wheelchair location data from a connected 215-bed acute care and 250-bed long-term care facility. Simulated scenarios varied in frequencies of patient wheelchair contamination and wheelchair disinfection in between trips. Clostridioides difficile and methicillin-resistant Staphylococcus aureus concentrations on patient hands at the end of wheelchair trips were estimated. Exposure reductions due to disinfection, assuming low real-world efficacies (50%, 70%, and 90%), were compared..In the simulation, when few patients introduced contamination to wheelchairs, disinfection in between patients 50% of the time decreased baseline (no disinfection) estimated exposures for the 50th wheelchair rider by >99.999%. When patients had a 50% chance of being contaminated before the wheelchair ride, disinfection did not reduce exposures consistently..The efficacy of disinfection in between patient rides as an exposure mitigation strategy likely depends on the frequency of infected patient wheelchair use..During outbreak, high contamination conditions, disinfection, alone, is not enough to protect patients from wheelchair-mediated exposures.
• Verhougstraete, M., Kennedy, M., Rose, J., Ikner, L. A., Ives, R., Troup, D., & Pearce-Walker, J. (2019). UVGI system impact on airborne indicators of common veterinary pathogens.. American Journal of Veterinarian Research.
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  Pearce-Walker, J. D.J. Troup, R. Ives, L.A. Ikner, J.B. Rose, M.A. Kennedy, M.P. Verhougstraete (Accepted). UVGI system impact on airborne indicators of common veterinary pathogens. American Journal of Veterinarian Research.
• Verhougstraete, M., Kuppravalli, A., Joshi, S., Heida, A., Hamilton, K. A., Haas, C. N., & Gerrity, D. (2021). Legionnaires' disease in dental offices: Quantifying aerosol risks to dental workers and patients.. Journal of occupational and environmental hygiene, 18(8), 378-393. doi:10.1080/15459624.2021.1939878
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  Legionella pneumophila is an opportunistic bacterial respiratory pathogen that is one of the leading causes of drinking water outbreaks in the United States. Dental offices pose a potential risk for inhalation or aspiration of L. pneumophila due to the high surface area to volume ratio of dental unit water lines-a feature that is conducive to biofilm growth. This is coupled with the use of high-pressure water devices (e.g., ultrasonic scalers) that produce fine aerosols within the breathing zone. Prior research confirms that L. pneumophila occurs in dental unit water lines, but the associated human health risks have not been assessed. We aimed to: (1) synthesize the evidence for transmission and management of Legionnaires' disease in dental offices; (2) create a quantitative modeling framework for predicting associated L. pneumophila infection risk; and (3) highlight influential parameters and research gaps requiring further study. We reviewed outbreaks, management guidance, and exposure studies and used these data to parameterize a quantitative microbial risk assessment (QMRA) model for L. pneumophila in dental applications. Probabilities of infection for dental hygienists and patients were assessed on a per-exposure and annual basis. We also assessed the impact of varying ventilation rates and the use of personal protective equipment (PPE). Following an instrument purge (i.e., flush) and with a ventilation rate of 1.2 air changes per hour, the median per-exposure probability of infection for dental hygienists and patients exceeded a 1-in-10,000 infection risk benchmark. Per-exposure risks for workers during a purge and annual risks for workers wearing N95 masks did not exceed the benchmark. Increasing air change rates in the treatment room from 1.2 to 10 would achieve an ∼85% risk reduction, while utilization of N95 respirators would reduce risks by ∼95%. The concentration of L. pneumophila in dental unit water lines was a dominant parameter in the model and driver of risk. Future risk assessment efforts and refinement of microbiological control protocols would benefit from expanded occurrence datasets for L. pneumophila in dental applications.
• Wilson, A. M., Verhougstraete, M. P., Beamer, P. I., King, M., 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.
• Gerba, C. P., Gerba, C. P., Reynolds, K. A., Reynolds, K. A., King, M. F., King, M. F., Beamer, P., Beamer, P., Verhougstraete, M., Verhougstraete, M., Wilson, A., & Wilson, A. (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.
• Pearce-Walker, J. I., Troup, D. J., Ives, R., Ikner, L. A., Rose, J. B., Kennedy, M. A., & Verhougstraete, M. P. (2020). Investigation of the effects of an ultraviolet germicidal irradiation system on concentrations of aerosolized surrogates for common veterinary pathogens. American journal of veterinary research, 81(6), 506--513.
• Pearce-Walker, J., Verhougstraete, M., Bright, K. R., Wilson, A. M., Canales, R. A., Canales, R. A., Wilson, A. M., Bright, K. R., Pearce-Walker, J., & Verhougstraete, M. P. (2020). Managing leafy green safety from adenoviruses and enteroviruses in irrigation water. Agricultural Water Management, 240, 106272.
• Verhougstraete, M. P., Pogreba-Brown, K., Reynolds, K. A., Lamparelli, C. C., Sato, M., 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.
• Verhougstraete, M. P., Wilson, A. M., Canales, R. A., Bright, K. R., & Pearce-Walker, J. (2020). Managing leafy green safety from adenoviruses and enteroviruses in irrigation water.. Agricultural Water Management, 240, 106272. doi:https://doi.org/10.1016/j.agwat.2020.106272
• 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.
• Wilson, A. M., Verhougstraete, M. P., Donskey, C. J., & Reynolds, K. A. (2020). An agent-based modeling approach to estimate pathogen exposure risks from wheelchairs. American Journal of Infection Control.
• Wilson, A., Donskey, C., Verhougstraete, M., & Reynolds, K. (2020). Estimating the Contribution of a Contaminated Wheelchair to Pathogen Spread With an Agent-Based Model. Infection Control & Hospital Epidemiology, 41(S1), s474--s474.
• Eisenburg, J., Eisenburg, J., Wade, T., Wade, T., Zanoli Satof, M., Zanoli Satof, M., Conde Lamparellie, C., Conde Lamparellie, C., Reynolds, K. A., Reynolds, K. A., Canales, R. A., Canales, R. A., Pogreba Brown, K. M., Pogreba Brown, K. M., Verhougstraete, M., & Verhougstraete, M. (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
• Madera-Garcia, V., Mraz, A. L., Lopez-Galvez, N., Weir, M. H., Werner, J., Beamer, P. I., & Verhougstraete, M. P. (2019). Legionella pneumophila as a Health Hazard to Miners: A Pilot Study of Water Quality and QMRA. WATER, 11(8).
• Munoz-Gutierrez, K. M., Canales, R. A., Reynolds, K. A., & Verhougstraete, M. P. (2019). Floor and environmental contamination during glove disposal. JOURNAL OF HOSPITAL INFECTION, 101(3), 347-353.
• Verhougstraete, M. (2019). Cost-benefit of point-of-use devices for lead reduction. Environmental Research.
• Verhougstraete, M., Werner, J. D., Beamer, P., & Madera-Garcia, V. (2018). Legionella is a Miner issue. International Journal of Mining Science and Technology.
• 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.
• 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).
• Lothrop, N., Bright, K. R., Sexton, J., Pearce-Walker, J., Reynolds, K. A., & Verhougstraete, M. P. (2018). Optimal strategies for monitoring irrigation water quality. AGRICULTURAL WATER MANAGEMENT, 199, 86-92.
• 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
• Nshimyimana, J. P., Martin, S. L., Flood, M., Verhougstraete, M. P., Hyndman, D. W., & Rose, J. B. (2018). Regional Variations of Bovine and Porcine Fecal Pollution as a Function of Landscape, Nutrient, and Hydrological Factors. JOURNAL OF ENVIRONMENTAL QUALITY, 47(5), 1024-1032.
• Verhougstraete, M. (2018). Comparison of Perceived and Observed Hand Hygiene Compliance in Healthcare Workers in MERS-CoV Endemic Regions. Healthcare.
• 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.
• Verhougstraete, M., Verhougstraete, M., Reynolds, K. A., Reynolds, K. A., Gerba, C. P., & Gerba, C. P. (2017). Lead in drinking water: Point of use cost benefit analysis.. Environmental Health Perspectives.
• Lothrop, N. Z., Bright, K., Sexton, J. D., Reynolds, K. A., & Verhougstraete, M. (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.
• Verhougstraete, M. (2016). On Tap: Water Issues: Global Concerns and Global Issues. Water Conditioning & Purification International.
  More info

  Trade journal article peer reviewed by a technical advisory committee. http://www.wcponline.com/2016/01/15/on-tap-water-issues-global-concerns-and-global-issues/
• Verhougstraete, M. (2016). Use of a portable air disinfecting system to remove seeded coliphage in hospital rooms. American Journal of Infection Control.
• 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), 714-715.
• Lamparelli, C. C., Pogreba-Brown, K., Verhougstraete, M. P., Sato, M. I., {de Castro Bruni}, A., Wade, T. J., & Eisenberg, J. N. (2015). Are fecal indicator bacteria appropriate measures of recreational water risks in the tropics: A cohort study of beach goers in Brazil?. Water Research, 87, 59--68.
• Lothrop, N., Wilkinson, S. T., Verhougstraete, M., Sugeng, A., Loh, M. M., Klimecki, W., & Beamer, P. I. (2015). Home Water Treatment Habits and Effectiveness in a Rural Arizona Community. WATER, 7(3), 1217-1231.
• Verhougstraete, M. (2015). Are fecal indicator bacteria appropriate measures of recreational water risks in the tropics: A cohort study of beach goers in Brazil?. Water Research.
• Verhougstraete, M. (2015). Lessons learned from implementing a wet laboratory molecular training workshop for beach water quality monitoring. PLoS ONE.
• Verhougstraete, M. (2015). Linking fecal bacteria in rivers to landscape, geochemical, and hydrologic factors and sources at the basin scale. Proceedings of the National Academy of Sciences.
• Verhougstraete, M. P., Brothers, S., Litaker, W., Blackwood, A. D., & Noble, R. (2015). Lessons Learned from Implementing a Wet Laboratory Molecular Training Workshop for Beach Water Quality Monitoring. PLOS ONE, 10(3).
• Verhougstraete, M. P., Martin, S. L., Kendall, A. D., Hyndman, D. W., & Rose, J. B. (2015). Linking fecal bacteria in rivers to landscape, geochemical, and hydrologic factors and sources at the basin scale. Proceedings of the National Academy of Sciences, 112, 201415836.
• 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.
• Verhougstraete, M. (2014). Microbial investigations of water, sediment, and algal mats in the mixed use watershed of Saginaw Bay, Michigan. Journal of Great Lakes Research.
• Verhougstraete, M. (2010). Cladophora in the Great Lakes: Impacts on beach water quality and human health. Water Science and Technology.

Presentations

• Madera-Garcia, V., Verhougstraete, M., Werner, J. D., Beamer, P., Beamer, P., Werner, J. D., Madera-Garcia, V., & Verhougstraete, M. (2018, May). Legionella is a Miner Issue. University of North Carolina Water Microbiology conference. Chapel Hill, NC.
• Pearce-Walker, J., Wilson, A., Canales, R., Bright, K., Gerba, C., & Verhougstraete, M. (2019, May). Adenovirus infection risk from irrigated leafy green consumption. University of North Carolina Water Microbiology conference. Chapel Hill, NC.
• Pogreba Brown, K. M., Mclain, J. E., Verhougstraete, M., Cooper, K. K., Cooper, K. K., Verhougstraete, M., Mclain, J. E., & Pogreba Brown, K. M. (2019, November). Breaking down scientific silos: using One Health to address the World’s wicked problems. TENWEST Impact Festival. Tucson, Arizona.
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  McLain, J.E. K. Cooper, K. Pogreba-Brown, and M. Verhougstraete. Breaking down scientific silos: using One Health to address the World’s wicked problems. Tucson, Arizona, October 14, 2019.
• Verhougstraete, M. (2019, April). There’s we in water. Georgia Southern Environmental Health Graduate seminar. Statesboro, Georgia: Georgia Southern.
• Verhougstraete, M. (2019, December). Development of Health Eects Endpoint Dose Response and QMRA Models for Two Healthcare Associated Infections MRSA and Clostroides dicile. The Society for Risk Analysis (SRA). Arlington, VA.
• Verhougstraete, M., & Beamer, P. (2019, April). PFAS report update. Pima Board of Health monthly meeting. Tucson, AZ: Pima Board of Health.
• Verhougstraete, M., & Nshimyimana, J. P. (2018, June). Regional variations of bovine and porcine fecal pollution. IAGLR 2018 Conference on Great Lakes Research. Toronto.
• Verhougstraete, M., & Zimmer-Faust, A. (2019, May). Young professionals workshop. University of North Carolina Water Microbiology conference. Chapel Hill, NC.
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  Lead a young scientist workshop for 33 student researchers. Included 6 senior mentors from around the world to discuss careers in federal, state, and local government, non-profit, industry, and academia. Helped students develop elevator speeches and practice.
• Verhougstraete, M., Gerald, J. K., Reynolds, K. A., & Gerba, C. P. (2019, June). Cost-Benefit of Point of Use Devices for Lead Reductions. American Water Works Association ACE 2019. Denver, CO: WQRF.
• Verhougstraete, M., Weir, M., & Miller, J. (2017, May). International Risk Consortium side event. University of North Carolina Water Microbiology conference. Chapel Hill, NC.
• Verhougstraete, M. (2016, December). Practical tips for effective water sampling. Washington State Fruit Tree Association annual meeting. Wenatchee, WA.
• Verhougstraete, M. (2016, June). Optimal strategies for monitoring irrigation water quality and the development of guidelines for the irrigation of food crops. Center for Produce Safety annual meeting. Seattle, WA.
• Verhougstraete, M. (2016, May). Optimal strategies for monitoring irrigation water quality and the development of guidelines for the irrigation of food crops. University of North Carolina Water Microbiology conference. Raleigh, NC.
• Verhougstraete, M. P., & Bright, K. (2015, July). Optimal strategies for monitoring irrigation water quality and the development of guidelines for the irrigation of food crops. Center for Produce Safety annual meeting. Atlanta, GA, USA: Center for Produce Safety.
• Verhougstraete, M. P., Martin, S., Kendall, A., Hyndman, D., & Rose, J. (2015, December). Linking fecal bacteria in rivers to landscape, geochemical, and hydrologic factors and sources at the basin scale. Michigan Department of Environmental Quality webinar. Lansing, Michigan, US: Michigan Department of Environmental Quality.

Poster Presentations

• Verhougstraete, M., Zimmer-Faust, A., White, M., & Pearce-Walker, J. (2019, April). Assessing the Efficacy of Antimicrobial Ear Drops for Microbial Reductions. University of Arizona Public Health Poster Forum. Tucson, AZ.
• Wagoner, R., & Verhougstraete, M. (2019, August). Addressing Water Quality Alongside Community Health Workers in a Farm Worker Community. International Society Of Exposure Science and International Society Of Indoor Air Quality And Climate. Kaunas, Lithuania.
• Troup, D., Verhougstraete, M., & Reynolds, K. A. (2017, April). Bioaerosol Reduction with a Passive Air Treatment System in a Controlled Chamber. MEZCOPH Student Poster Forum. Tucson, AZ.

Others

• Beamer, P., Pountain, M., Nematollahi, A., Verhougstraete, M., & Pearce-Walker, J. (2019, December). Environmental Toxic Substance Assessment: Per- and Polyfluoroalkyl Substances (PFAS) in Pima County Water. Pima County Health Department.
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  A review report on PFAS in Pima County, Arizona groundwater and the health effects of PFAS on humans.
• Pearce-Walker, J., Verhougstraete, M., Nematollahi, A., Pountain, M., & Beamer, P. (2019, December). Environmental Toxic Substance Assessment: Per- and Polyfluoroalkyl Substances (PFAS) in Pima County Water.
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  A review report on PFAS in Pima County, Arizona groundwater and the health effects of PFAS on humans.
• Verhougstraete, M. (2020, January). Combined Surface Sampling and Quantitative Microbial Risk Assessment Modeling To Optimize Surface Cleaning For Targeted HAI Reduction.
  More info

  Final report for CDC funded research project. A comprehensive, 200 page report. J. Pearce-Walker, J., A. Yoder, M.H. Weir, and M. Verhougstraete. 2019. Combined Surface Sampling and Quantitative Microbial Risk Assessment Modeling To Optimize Surface Cleaning For Targeted HAI Reduction. For Center for Disease Control and Prevention.
• 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..
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  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.