The recent progress of our understanding of the pathophysiology of human immunodeficiency virus (HIV) infection and the availability of new antiretroviral compounds has markedly improved the prognosis of patients infected with HIV. It has been postulated as early as 1991 that potent community-wide treatment of HIV infection could paradoxically lead to an increased spread of the HIV epidemic if treatment is not associated with a reduced infectivity of HIV. In the past few years, several groups have demonstrated a good correlation of the quantity of HIV present in semen with factors that are known to increase the likelihood of sexual transmission of HIV. A similar correlation has recently been demonstrated for the presence of HIV in female genital secretions. During the past year, a number of studies have demonstrated a marked effect of antiretroviral treatment on the shedding of HIV in the male and female genital tract, indicating a potential role of antiretroviral treatment for the prevention of HIV infection. Although potent antiretroviral therapy is beneficial on a public health basis, patients with no detectable virus in their blood or semen under treatment should not be considered non-infectious and patients should keep up with safer sex practices.