Prevention of human immunodeficiency virus and AIDS: postexposure prophylaxis (including health care workers).

Postexposure prophylaxis (PEP), which is designed to prevent human immunodeficiency virus (HIV) infection after an exposure, is one of several strategies for HIV prevention. PEP was first used after occupational HIV exposures in the late 1980s, with the Centers for Disease Control and Prevention issuing the first set of guidelines that included considerations regarding the use of antiretroviral agents for PEP after occupational HIV exposures in 1990. Use of PEP has been extended to nonoccupational exposures, including after sexual contact or injection-drug use. This article provides a rationale for PEP, assessment of the need for PEP, and details of its implementation.