We examined the influence of job category, source patient HIV status, and e
xposure type as predictors of whether health care workers initiated antiret
roviral prophylaxis after potential blood-borne pathogen exposures. Of 639
exposures over an 18-month period, 82 individuals (13%) elected to receive
prophylaxis, of whom 66% took medications for fewer than 96 hours and: 12%
completed a 4-week course. Reasons for early drug discontinuation included
confirmation of source patient HN-negative serological status (65%), gastro
intestinal side effects (13 %) headache (4 %), and personal decision after
counseling/other input (18 %). Individuals exposed to HIV-positive source p
atients were more likely to initiate prophylaxis (odds ratio [OR], 5.1; 95%
confidence interval [CI] 2.6 to 9.9). Licensed nurses were less likely tha
n others to accept prophylaxis (OR, 0.5; 95% CI; 0.3 to 0.8), whereas physi
cians and medical students were more likely to accept prophylaxis (OR, 1.9;
95% CI, 1.1 to 3.3).