William A. Petri, Jr., M.D., Ph.D. studies immunology and molecular pathogenesis of enteric infections and their consequences. The scope of research includes molecular parasitology of Entamoeba, innate immune host defense against Clostridium difficile, and in Bangladesh acquired immunity to Cryptosporidium. We study infections in mouse models, in humans (including clinical trials) and at the lab bench. Petri leads the PROVIDE study of the Bill & Melinda Gates Foundation that is exploring in Bangladesh and India the pathogenesis of enteric environmental dysfunction (EED) and its association with oral poliovirus and rotavirus vaccine failures, malnutrition and neurocognitive developmental delay. Petri has received from Governor Terry McAuliffe both the Commonwealth of Virginia Outstanding Faculty Award (2014) and the Outstanding Scientist Award (2017). He has been recognized at UVa with the Kadner Award for Graduate Teaching, the All-University Teaching, and Inventor of the Year Awards. Petri has served as President of the American Society of Tropical Medicine and Hygiene and Editor of Infection and Immunity, and is currently Associate Editor for PLoS Pathogens, Clinical Infections Diseases and Trends in Molecular Medicine. He has received the Oswald Avery Award of the Infectious Diseases Society of America, the Burroughs Wellcome New Investigator and Scholar Awards in Molecular Parasitology, and the Lucille P. Markey Scholar Award in Biomedical Research. He has served continuously since 1993 on advisory committees for the NIH. Bill Petri received the MD and PhD (Microbiology) degrees from UVA, did medicine residency at Case Western and returned to UVA for infectious diseases fellowship. He spends 3 months of every year caring for patients on the general medicine and infectious diseases services and the remainder is focused on research on infectious diseases, especially the molecular pathogenesis of diarrheal infections in children living in poverty in Bangladesh and the immunology of C. difficile infection in a mouse model and in patients at UVA hospital.