People who are exposed to HIV by sexual assault, accidents, or isolated episodes of unprotected sex or IV drug use should receive antiretroviral drugs to prevent infection, according to new guidelines from the CDC. Previously, postexposure HIV prophylaxis was recommended only for healthcare workers exposed to HIV while on the job.

The new guidelines call for giving a 28-day course of antiretroviral therapy known as nonoccupational postexposure prophylaxis (nPEP) to anyone who seeks care within 72 hours of being exposed to a potentially infectious body fluid from a person known to have HIV when the risk of transmission is high.

If a patient presents after 72 hours or the risk of transmission is low, nPEP is not recommended. It's also not recommended for habitual IV drug users who share needles or people who frequently engage in unprotected sex because these patients would require continuous antiretroviral therapy. Instead, the guidelines indicate that these patients should be taught intensive, risk-reduction interventions.

Source: Centers for Disease Control and Prevention. (2005). Antiretroviral postexposure prophylaxis after sexual, injection-drug use, or other nonoccupational exposure to HIV in the United States: Recommendations from the U.S. Department of Health and Human Services. MMWR, 54(RR2), 1.