Howard Markel, M.D., Ph.D., is the George E. Wantz Distinguished Professor of the History of Medicine and director of the Center for the History of Medicine at the University of Michigan. His books include Quarantine! and When Germs Travel. His articles have appeared in The New York Times, The Journal of the American Medical Association, and The New England Journal of Medicine, and he is a frequent contributor to National Public Radio. Markel is a member of the Institute of Medicine of the National Academy of Sciences and lives in Ann Arbor, Michigan.