One of the most serious threats medical students face during their clinical training is the possibility of exposure to blood-borne pathogens, with the attendant risk of infection with the human immunodeficiency virus (HIV), hepatitis B virus (HBV), or hepatitis C virus (HCV). Yet the problem of exposure to contaminated blood among the estimated 50,000 medical students in the United States,1 about half of whom are receiving clinical training in the nation's 126 medical schools at a given time, has received little attention.213 The risk of percutaneous injury to health care workers has been well documented.1416 It is estimated . . .