Edward T. Ryan is an American microbiologist, immunologist, and physician at Harvard University and Massachusetts General Hospital. Ryan served as President of the American Society of Tropical Medicine and Hygiene from 2009-2010. Ryan is Professor of Immunology and Infectious Diseases at the Harvard T.H. Chan School of Public Health, Professor of Medicine at Harvard Medical School, and Director of Global Infectious Diseases at the Massachusetts General Hospital. Ryan's research and clinical focus has been on infectious diseases associated with residing in, immigrating from, or traveling through resource-limited areas. Ryan is a Fellow of the American Society of Microbiology, the American Society of Tropical Medicine and Hygiene, the American College of Physicians, and the Infectious Diseases Society of America. Ryan's investigative work has focused on tropical, emerging and global infectious diseases, especially understanding host-pathogen interactions, and relating that knowledge to the discovery, development, and implementation of advanced diagnostics and vaccines. Particular areas of focus include cholera, typhoid, shigella, and the transmission of infectious diseases by humans crossing international borders.
Together with Dr. Stephen Calderwood, Dr. Jason Harris, Dr. Regina LaRocque, Dr. Daniel Leung, Dr. Richelle Charles and colleagues at Harvard, and Dr. Firdausi Qadri and colleagues at the ICDDRB, Ryan has focused on advancing understanding of host-pathogen and immune responses during cholera, a human-restricted infection that largely afflicts impoverished individuals in resource-limited areas of the world. Ryan’s investigative work is supported by the U.S. National Institutes of Health. Significant contributions include the finding that contrary to the previously established paradigm, cholera induces a pro-inflammatory response in afflicted humans, and that this response correlates with magnitude and duration of immunity against cholera. Ryan has particularly focused on analyzing immune responses against the polysaccharide coating of the Vibrio cholerae organism, the O-specific polysaccharide, working with Dr. Paul Kovac of the National Institutes of Health. Immune responses to OSP mediate protection against cholera in humans. This work has informed advanced vaccine development.
Typhoid
Ryan's efforts in typhoid have largely focused on using high throughput analyses to characterize both pathogen responses during typhoid fever, including bacterial gene expression in infected humans, and human immune responses to bacterial infection. This collaborative work with Charles and Qadri has identified a biomarker of chronic carriage of the bacillus that causes typhoid fever, and included the first transcriptional analysis of a bacterial pathogen directly in the bloodstream of an infected human; work that was performed in humans with typhoid and paratyphoid fever in Bangladesh. This work has informed diagnostic assay development.
Shigella
Ryan’s efforts on shigellosis have focused on vaccine development and host-pathogen interactions. In 2006, Ryan showed that administration of antibiotics to children with shigellosis in Bangladesh did not increase toxin production by the bacterium. This finding supports targeted antimicrobial treatment of humans with shigellosis. Such treatment is usually contraindicated in humans infected with Shiga-toxin expressing E. coli infection, in whom such treatment substantially increasing the risk of renal failure.
Ryan co-directs the Global TravEpiNet consortium and program with Dr. Regina LaRocque. GTEN's focus has been to advance the health of U.S. residents who cross international borders. The GTEN network and its support tools were developed with support from the Centers for Disease Control and Prevention with the goal of lessening illness relating to crossing international borders and the likelihood of disease importation into home communities. This program has included the development of a number of public health programs and resources, including web tools that provide up-to-date recommendations on health interventions and risks; these resources are maintained within the Heading Home Healthy Program.
Ryan teaches at Harvard College, Harvard Medical School and the Harvard School of Public Health. He trains post-doctoral fellows and students in his laboratory, as well as intern, resident, fellow and student clinicians-in-training at the Massachusetts General Hospital. He directs a Fogarty International Center Training program between the Massachusetts General Hospital and the ICDDRB in Bangladesh.
Ryan has authored or co-authored over 300 publications, including over 200 in the peer-reviewed literature. He also serves in editorial capacities for PLoS Neglected Tropical Diseases, the CDC Yellow Book, Microbes and Infections, and is Senior Editor of Hunter’s Tropical Infectious Diseases.