Talha Riaz

Interests

Teaching

Medical students, residents and fellows

Research

Orthopedic infectious diseasesCardiovascular infectious diseasesCoccidiodomycosis

Courses

No activities entered.

Scholarly Contributions

Chapters

• Riaz, T., & Tande, A. J. (2021). Bone and Joint Infections. In A rational approach to clinical infectious disease. Elsevier. doi:10.1016/b978-0-323-69578-7.00013-2
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  This chapter reviews the commonly encountered infectious diseases pertaining to bone and joints, beginning with native septic arthritis, which can be further divided into gonococcal and nongonococcal arthritis. Staphylococcus aureus or streptococci are responsible for most cases of native arthritis. Other etiologies, such as fungal and viral arthritides, are also described. We also describe vertebral osteomyelitis, as well as osteomyelitis of the appendicular skeleton. S. aureus is the commonly implicated pathogen here too. Treatment involves several weeks of pathogen-directed antibiotics, with surgical debridement varying from case to case. In addition, we describe osteomyelitis in the diabetic population and patients with vascular disease. Periprosthetic joint infections (PJIs) are among the most dreadful complications of joint arthroplasty. We review risk factors, clinical presentation, and treatment approach, which varies from case to case. However, several weeks of antibiotics—up to 6 weeks—are typically administered, followed by suppressive courses in select patients. We also describe suppurative tenosynovitis. This can involve flexor or extensor tendons of the extremities. Diagnosis is typically based on clinical presentation, and therapy consists of appropriate antibiotics and incision and drainage to prevent tendon necrosis. Mycobacterial tenosynovitis warrants special attention, as treatment is typically prolonged.

Journals/Publications

• Riaz, T. (2023). Disseminated Histoplasmosis in an Immunocompetent Patient from Southern Arizona. Journal of Fungi.
• Riaz, T. (2023). Severe Musculoskeletal Manifestations of lower extremity Coccidioidomycosis: A case series. Journal of Bone and Joint Infection.
• Riaz, T. (2024). Syndrome of Inappropriate Antidiuretic Hormone Release Secondary to Central Nervous System Coccidioidomycosis with Vasculitis . British Medical Journal.
• King, R., Sekar, P., Patel, H., Naveed, M., Aqtash, S., Adroja, S., Jacob, D., & Riaz, T. (2023). CNS toxoplasmosis, a rare presentation in a patient with Myasthenia Gravis. IDCases, 32, e01780.
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  We report the case of a 78-year-old man with a past medical history of non-Hodgkin's lymphoma s/p chemotherapy and Myasthenia Gravis on chronic mycophenolate mofetil (MMF), who presented with altered mental status and was found to have ring enhancing brain lesions. A brain biopsy revealed organisms consistent with . Cerebral toxoplasmosis has been rarely reported in patients with hematologic malignancies or in those receiving immunosuppressive agents. There needs to be a high degree of suspicion for in HIV-negative individuals who are on immunosuppressants drugs including MMF.
• Riaz, T., Berbari, E., Huddleston, P. M., Ross, C., Tande, A. J., Diehn, F., & Howard, M. (2022). Utility of disc space aspirate cell counts and differentials in the diagnosis of native vertebral osteomyelitis. Journal of bone and joint infection. doi:10.5194/jbji-7-213-2022
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  Abstract. Background: Aspiration of intervertebral disc space is often done to confirm the diagnosis of native vertebral osteomyelitis. A study has not been done examining the utility of cell counts and differentials of the aspirated fluid in diagnosing native vertebral osteomyelitis (NVO). Methods: In this feasibility study, we prospectively enrolled patients with a suspected diagnosis of NVO referred to the Division of Neuroradiology for image-guided needle aspiration of the intervertebral disc. In this study, manual cell count was done on the aspirated fluid, followed by a differential cytospin technique and touch prep. We obtained demographic, lab, and microbiologic data and used the receiver operating curve (ROC) for statistical analysis. Results: Over 12 months, we performed 17 aspirates on 14 patients. The median age was 70.5 years (range: 45–77). The median manual cell count on the aspirated fluid was 52 cells µL−1 (range: 0–6656), the median neutrophil percentage on the touch prep slide was 73 % (range: 5 %–100 %), and the median neutrophil percentage on the cytospin slide was 82 % (range: 0 %–100 %). Routine bacterial cultures were positive in five cases, and the 16S ribosomal RNA gene polymerase chain reaction was positive in two cases. The optimal cutoff for a cell count of 104 total nucleated cells offered a sensitivity and specificity of 86 %, and a neutrophil cutoff of 83 % was associated with a 71 % sensitivity and specificity. Conclusion: An image-guided aspirated specimen leukocyte differential of ≥83 % neutrophils or a leukocyte count of ≥104 µL−1 was a sensitive and specific test for diagnosing patients with suspected NVO. Additionally, more extensive studies are warranted to confirm the findings.
• Riaz, T., Lao, N., Idowu, A. B., Sommer, J., & Adebolu, O. I. (2022). Vertebral osteomyelitis and epidural abscess due to Listeria monocytogenes – case report and review of literature. Journal of bone and joint infection. doi:10.5194/jbji-7-75-2022
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  We describe a case of native vertebral osteomyelitis (NVO) secondary to Listeria monocytogenes in a patient with polymyalgia rheumatica receiving chronic steroids. Treatment required surgical debridement of the epidural phlegmon and combination therapy with intravenous ampicillin and gentamicin.
• Riaz, T., Sia, I. G., Osmon, D. R., Lehman, J. S., Schuetz, A. N., Rizzo, M., Enzler, M. J., & Collins, M. S. (2021). Left hand extensor tenosynovitis due to Histoplasma capsulatum complicated by immune reconstitution inflammatory syndrome. Journal of bone and joint infection. doi:10.5194/jbji-6-355-2021
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  We describe a case of left hand extensor tenosynovitis due to histoplasmosis in a patient with dermatomyositis on chronic immunosuppression. Treatment involved surgical debridement and antifungal therapy. The patient experienced paradoxical worsening of tenosynovial inflammation during de-augmentation of immunosuppression felt to be immune reconstitution inflammatory syndrome.
• Riaz, T., Marculescu, C. E., Osmon, D. R., Salgado, C. D., Demos, H. A., Steed, L. L., & Tande, A. J. (2020). Risk Factors for Fungal Prosthetic Joint Infection. Journal of bone and joint infection. doi:10.7150/jbji.40402
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  Abstract. Background: Fungal prosthetic joint infections (PJIs) are rare and often associated with poor outcome; however, risk factors are not well described.Methods: This was a retrospective case control study among all patients with PJIs from 2006-2016 at two major academic centers. Each fungal PJI case was matched 1:1 with a bacterial PJI control by joint (hip, knee, shoulder) and year of diagnosis. We compared demographics, comorbidities, and clinical characteristics between cases and controls using chi square/Fisher's exact or Wilcoxon rank sum test. Independent risk factors were identified with multivariable logistic regression.Results: Forty-one fungal PJIs occurred over the study and 61% were due to Candida albicans. The hip was involved in 51.2% of cases, followed by the knee (46.3%). Compared to bacterial PJI, fungal PJI cases were more likely to have received antibiotics within the previous 3 months (70.7% vs 34%, P=.001), wound drainage lasting >5 days (48% vs 9%, P=.0002), had a lower median CRP (2.95 mg/dl vs 5.99, P=.013) and synovial fluid white blood cell count (13,953 cells/mm3 vs 33,198, P=.007), and a higher proportion of prior two-stage exchanges (82.9% vs 53.6%, P=.008). After controlling for center, prolonged wound drainage (OR, 7.3; 95% CI, 2.02-26.95) and recent antibiotics (OR, 3.4; 95% CI, 1.2-9.3) were significantly associated with fungal PJI.Conclusion: In our study, Candida albicans was the most common species in fungal PJIs and prolonged wound drainage and recent antibiotics were independent risk factors. These clinical characteristics may help providers anticipate fungal PJI and adjust management strategies.
• Riaz, T., Nienaber, J. J., Baddour, L. M., Walker, R. C., Park, S. J., & Sohail, M. R. (2014). Cardiovascular implantable electronic. PACE - Pacing and Clinical Electrophysiology, 37(Issue 2). doi:10.1111/pace.12240
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  Background Most patients with left ventricular assist devices (LVADs) have concomitant cardiovascular implantable electronic devices (CIEDs). However, clinical presentation and outcome of CIED infection in the setting of LVAD has not been previously described. Methods We retrospectively reviewed 247 patients who underwent LVAD implantation at Mayo Clinic campuses in Minnesota, Arizona, and Florida, from January 2005 to December 2011. Demographic and clinical data of patients who met criteria for CIED infection were extracted. Results Of 247 patients with LVADs, 215 (87%) had CIED at the time of LVAD implantation and six (2.8%) subsequently developed CIED infections. Three patients developed CIED lead-related endocarditis and the other three had pocket infection. All three instances of CIED pocket infection were preceded by device generator exchange, whereas all three patients with CIED lead-related endocarditis had prior LVAD-related infections. Causative pathogens included Pseudomonas aeruginos (1), coagulase-negative staphylococci (2), methicillin-resistant Staphylococcus aureus (1), a gram-positive bacillus (1), and culture negative (2). All patients underwent complete CIED removal along with antimicrobial therapy. The three patients with CIED lead-related endocarditis and prior LVAD infections received chronic suppressive antibiotic therapy, and one patient had LVAD exchange. All but one remained alive at the last follow-up with a median duration of 15 months (7-46 months) from the time of CIED infection. Conclusion Patients who are receiving LVAD therapy and develop CIED infection should be managed with complete CIED removal. Chronic suppressive antibiotic therapy is warranted in cases that have concomitant LVAD infection. ©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.

Others

• Riaz, T. (2023, jul). Disseminated Coccidioides infection with CNS and MSK involvement in a patient with MS.