David Nelson is Chair and Professor of the Department of Pediatrics, as well as being Chief of Ambulatory Services at Georgetown University Hospital. He is also a Fellow of the American Association of Physicians (FAAP). He has expertise on lead poisoning and he was actively involved in elucidating the role of aspirin in the etiology of Reyes syndrome. His focus is in pediatrics and his special interests include: immunizations, epidemiology, nosocomial infections, lead poisoning and international adoptions.