Preexposure Chemoprophylaxis for HIV Prevention in Men Who Have Sex with Men

In this study, 2499 HIV-seronegative men or transgender women who were at high risk for HIV acquisition were enrolled in a trial of daily emtricitabine plus tenofovir versus placebo. Those receiving the antiretroviral medication had a 44% reduction in HIV incidence. A total of 2.7 million new infections with the human immunodeficiency virus (HIV) were diagnosed worldwide in 2008, according to the Joint United Nations Program on HIV/AIDS (UNAIDS). Combination antiretroviral therapy for patients with HIV infection restores health and may decrease the transmission of the virus to uninfected partners. 1 Therapy also decreases mother-to-child transmission. 2 Postexposure chemoprophylaxis is recommended after occupational or nonoccupational exposure to HIV-infected fluids. 3 The use of such chemoprophylaxis requires that people recognize when they might have been exposed to HIV and that they start therapy within 72 hours. Both challenges are substantial limitations to the use of . . .