Robert Orenstein DO FIDSA, FACP
HIV/AIDS Medicine, Healthcare Associated Infections, Transplant/Immunocompromised States, International Health, Travel & Tropical
Professor of Medicine, Clinical Scholar University of Arizona, College of Medicine Tucson Tucson, Arizona
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5777 E Mayo BlvdPhoenix, AZ 85054
Phone+1 480-301-8000
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Summary
- Robert Orenstein, DO, based in Tucson, AZ, is an infectious disease specialist with a focus on healthcare-associated infections, and transplant/immunocompromised states and HIV/AIDS medicine. He completed his D.O. at Des Moines University College of Osteopathic Medicine and pursued residencies and fellowships in internal medicine and infectious diseases. His previous work history includes leading the HIV/AIDS Programs at the McGuire VA Medical Center and VCU Medical Centers in Richmond, Virginia; serving as a consultant in infectious diseases and an associate hospital epidemiologist at the Mayo Clinic in Rochester Minnesota and then as chairman of infectious diseases at Mayo Clinic Arizona. He currently is a member of the Banner University Medical Group in Tucson with the Division of Infectious Diseases and Professor of Medicine and Clinical Scholar at the University of Arizona College of Medicine in Tucson. He previously was a professor of medicine at the Mayo Clinic College of Medicine and Science and has held various roles, including Consultant and Chair of the Division of Infectious Diseases at Mayo Clinic Arizona for 13 years. He was one of the institutional leaders through the COVID-19 pandemic. Dr. Orenstein has expertise in managing HIV/AIDS, Orthopedic infections, complex surgical infections, multiply resistant and infections in immunocompromised hosts, mycobacterial infections, and C. diff colitis. he is recognized as a national expert in the use of microbiota therapies for recurrent C. difficile infections. His work includes numerous publications and participation in clinical trials, and he has received several awards, including the Above and Beyond Clinician Award from Mayo Clinic Arizona.
Education & Training
Virginia Commonwealth University1991 - 1993
Geisinger Health System (Danville)Residency, Internal Medicine, 1988 - 1991- Botsford General HospitalInternship, 1987 - 1988
Des Moines University College of Osteopathic MedicineClass of 1987, D.O., Sigma Sigma Phi- Trinity CollegeBS, Biochemistry , 1977 - 1981
Certifications & Licensure
AZ State License 2010 - 2027
MN State License 2002 - 2026
VA State License 1991 - 2008
PA State License 1989 - 2002
American Board of Internal Medicine Internal Medicine- American Board of Internal Medicine Infectious Disease
American Academy of HIV MedicineHIV- International Society for Travel MedicineCertificate in Travel Health
Awards, Honors, & Recognition
- Featured Educator Infectious Diseases Society of America, 2026
- Above and Beyond Clinician Award Mayo Clinic Arizona, Dept of Medicine, 2021
- Senior Fellow Academy of Academic Excellence- Mayo Clinic, 2020
Clinical Trials
- Study of Merimepodib in Combination With Remdesivir in Adult Patients With Advanced COVID-19 Start of enrollment: 2020 Jun 16
Publications & Presentations
PubMed
- 13 citationsSafety and Efficacy of Fecal Microbiota, Live-jslm (REBYOTA®), for the Prevention of Recurrent Clostridioides difficile Infection in Participants With Inflammatory Bow...Jessica R Allegretti, Paul Feuerstadt, Whitfield L Knapple, Robert Orenstein, Philippe Pinton
Inflammatory Bowel Diseases. 2025-08-01 - 11 citationsSafety and Tolerability of CP101, a Full-Spectrum, Oral Microbiome Therapeutic for the Prevention of Recurrent Clostridioides difficile Infection: A Phase 2 Randomized...Jessica R Allegretti, Colleen R Kelly, Thomas Louie, Monika Fischer, Susy Hota
Gastroenterology. 2025-02-01 - Integrated analysis of the safety of fecal microbiota, live-jslm in adults with recurrentinfection from five prospective clinical trials: an update.Christine Lee, Paul Feuerstadt, Thomas Louie, Lindy Bancke, Beth Guthmueller
Therapeutic Advances in Gastroenterology. 2025-01-01
Journal Articles
- TNF-Inhibitors and Infection.Orenstein R, Matteson EL, Infect Med 2006; 23:99-114
- Infections related to TNF-Inhibitors.Orenstein R, Expert Rev Dermatol 2006; 1(5): 757-769
- Opportunistic Infections associated with TNF-alpha Treatment.Orenstein R, Matteson EL, Future Rheumatol 2007;2:567-576
Books/Book Chapters
Abstracts/Posters
- Staged Approach to the reduction of C. difficile infection.Orenstein R, Thompson RL, Rosenblad M, Patel R, Annual Meeting of the Society for Healthcare Epidemiology of America, San Diego, CA
- Sustained Elimination of C. difficile Infection.Orenstein R, Fedraw L. Aronhalt K, McManus J, Link M, Annual Scientific Meeting of the Society for Healthcare Epidemiology of America, Dallas, TX
- A simple pre-operative prediction tool for surgical site infection in vascular surgery.Leekha S, Thompson RL, Sampathkumar P, Lahr B, Duncan A, Orenstein R, 5th Decennial International Conference on Healthcare Associated Infections, SHEA, CDC, APIC, IDSA, Atlanta, Georgia
Lectures
- Multiple Small Feedings of the Mind, Infectious Diseases.American College of Physicians Annual Meeting
- How to use antibiotics effectively in the outpatient arena.Primary Care Grand Rounds, McGuire VA Medical Center, Richmond, VA
- HIV in the Elderly.Division of Geriatrics Grand Rounds, Hunter Holmes McGuire VA Medical Center, Richmond, VA
Press Mentions
Stopping the Cycle of C. DiffFebruary 8th, 2023- Ferring to Present Analyses for Investigational Microbiota-Based Live Biotherapeutic RBX2660 in Patients with Recurrent C. Difficile Infection at ACG 2022October 11th, 2022
- “All About the Mission”August 1st, 2022
Professional Memberships
- Member
- Fellow
- Fellow
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