A 29-year-old physician accidentally sticks herself in the thumb after drawing blood during a cardiopulmonary resuscitation involving a man with HIV who was hospitalized for severe pneumonia. The site of the needlestick in the thumb bled for approximately 2 minutes. The source patient has not been engaged in medical care and laboratory studies obtained at the time of hospital admission 3 days prior showed a CD4 count of 148 cells/mm³ and an HIV RNA of 27,450 copies/mL.