Antiretroviral agents used by HIV-uninfected persons for prevention: pre- and postexposure prophylaxis.

Prophylactic use of antimicrobial agents and microbicides has been proven for many infections, including surgical, gastrointestinal, upper respiratory, and meningococcal infections. Antiretroviral therapy for pregnant women prevents mother-to-child transmission of human immunodeficiency virus (HIV), which has become rare in settings where access to therapy is widespread. Postexposure prophylaxis after needlestick injury or significant sexual exposure is recommended on the basis of animal studies and case-control observational studies, although use of these interventions is limited to those who recognize exposure, have access, and have the power to use the interventions. Clinical trials are evaluating whether regular or preexposure use of antiretroviral therapy provides additional protection for persons at high risk of infection who are also offered standard prevention care, including HIV testing, counseling, condoms, and management of sexually transmitted infections. Trials are evaluating topical or oral use. Concerns have arisen with regard to optimal dosing strategies, costs, access, drug resistance, risk behavior, and the role of communities. Future implementation, if warranted, will be guided by the results of clinical trials in progress and engagement of communities exposed to HIV.