Mark Riddle

Mark Riddle, M.D., Dr.P.H.

Associate Dean of Clinical Research, Professor


Dr. Riddle is a retired Captain in the Medical Corps of the United States Navy and boarded in General Public Health & Preventive Medicine. He has over 15 years in the field of applied clinical research and epidemiology ranging from pre-clinical vaccine development and clinical vaccine and drug development, to vaccine health economics and research related to the chronic health consequences of acute infection. His experience has been primarily gained from activities in a US Department of Defense (DoD) interdisciplinary research and development setting, but he has also lived and worked overseas (Cairo, Egypt), and has active collaborations with academia, industry and philanthropic global health organizations. He's held major leadership positions such as Director of the US DoD program to develop new vaccines against ETEC, Shigella and Campylobacter and Chair of the Department of Preventive Medicine and Biostatistics at the Uniformed Services University. Dr. Riddle has lead activities and efforts in developing and implementing guidelines in enteric diseases for national and international professional societies, and has made key contributions in defining the burden of chronic disease sequelae of acute enteric infections through epidemiology, proteomics and systems biology approaches. He is the co-author of over 180 peer reviewed publications, several book chapters, and serves actively in a number of professional societies and editorial boards. To achieve the appropriate life balance he enjoys flysfishing, clawhammer banjo, hiking, skiing and family.

Contributions to Science

Much of Dr. Riddle's career has involved work in travelers' diarrhea epidemiology and clinical management and has led to a number of recent contributions to the scientific knowledge base in the basic epidemiology of infectious gastroenteritis, including disease incidence and etiology. This research while not leading to any specific discovery has highlighted some important features including the cost-of-illness from a military and societal perspective, as well as identification of a critical gap in current practice management of a very common and disabling condition. As a direct result of this work, a large randomized controlled trial was executed and served as the basis for the development of new Clinical Practice Guidelines and changed the standard of care for the US military. This research has also had an impact on management of these infections in the civilian traveler setting in the US and internationally and lead to both American College of Gastroenterology and International Society of Travel Medicine Guidelines.

Growing out of work on studying the epidemiology of acute travelers' diarrhea in military service members, he worked with a team of collaborators to expand understanding of the burden of the overlooked chronic health consequences. Through use of large Department of Defense medical encounter databases we embarked on a number of studies which both corroborated and identified novel associations between common acute enteric infections and gastrointestinal chronic health consequences. These studies have emphasized factors of etiology, highlighted an unrecognized burden, and provided a strong base on which to conduct mechanistic studies to move beyond association and understand disease mechanisms. In addition, this body of work has had significant impacts at the national level at the level of policy and decision makers including the Institute of Medicine and Department of Veterans Affairs Department.

Based on the strong fundamental epidemiological research that Dr. Riddle's group has conducted, they initiated a number of research activities aimed at understanding the mechanism of chronic gastrointestinal disorders that appear to be triggered by acute enteric infections. The recent decade has seen an expansion of high throughput technologies to explore the fundamentals of the broad host-response interaction to inform disease pathogenesis and ultimately inform effective mitigation strategies. Dr. Riddle's research has indicated some interesting preliminary findings related to markers of post-infectious irritable bowel syndrome, as well as biomarkers predicting a complicated course of inflammatory bowel disease which precede disease onset. These observations have contributed new insights as well as explored the possibilities of serum systems biology.

Professional experience

  • Professor and Chair, Department of Preventive Medicine and Biostatistics (2017 - 2019) F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, MD, USA
  • Staff Physician, International Travel Medicine Clinic (2009 - 2019) Walter Reed National Military Medical Center, Bethesda, MD, USA
  • Director, U.S. Military Diarrheal Diseases Vaccine Research Program (2015 - 2017) US Army Medical Research and Materiel Command, Fort Detrick/Silver Spring, MD, USA
  • Director, Enteric Diseases Department (2013 - 2015) Naval Medical Research Center, Silver Spring, MD, USA
  • Deputy Director, Head, Clinical Trials & Epidemiology Division (2006 - 2013) Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD, USA
  • Head, Epidemiology and Clinical Trials (2004 - 2006) US Naval Medical Research Unit No.3, Cairo, Egypt


  • UNIVERSITY OF CALIFORNIA AT DAVIS, Davis, CA Zoology & Human Development (BS/BS, cum laude)
  • TULANE UNIVERSITY SCHOOL OF MEDICINE, New Orleans, LA Doctor of Medicine (MD)
  • TULANE SCHOOL OF PUBLIC HEALTH & TROPICAL MEDICINE, Master of Public Health and Tropical Medicine (MPH&TM)
  • UNIFORMED SERVICES UNIVERSITY, Bethesda, MD Doctor of Public Health (DrPH)
  • ADVANCED COURSE OF VACCINOLOGY, Fondation Mérieux (2009)