Risk factors and changes in sexual behavior in male homosexuals who seroconverted for human immunodeficiency virus antibodies.

In Amsterdam, The Netherlands, a cohort of 982 homosexual and bisexual men has been studied since 1984. Of these, 238 men had antibodies to the human immunodeficiency virus at the onset of the study, and 84 men seroconverted while under study. For each of these seroconversions, two participants who remained seronegative were chosen for comparison, taking the seroconversion date as a reference. This offered an opportunity to study any changes that may have occurred longitudinally, i.e., over time. Risk factors for seroconversion were studied along with changes in sexual behavior relative to the moment of seroconversion. The number of different partners in anogenital receptive intercourse and a history of syphilis or anogenital herpes simplex were found to be predictors for human immunodeficiency virus seroconversion. The data suggest that, prior to seroconversion, there is a peak in riskful sexual behavior and that the "decline" often observed immediately after seroconversion is, in fact, an indication of a return to "normal" sexual activity.