Predictors of unprotected sexual contacts in HIV-infected persons in Switzerland

Predictors of sexual risk behavior with regular and casual partners among HIV-infected heterosexual and gay persons were addressed. Sociodemographic data as well as self-and interviewer-reported data on sexual behavior were obtained from 117 asymptomatic HIV-infected persons enrolled in the Zurich part of the Swiss HIV Cohort Study (SHCS). Participants who reported sexual intercourse at least once (vaginal and/or anal) without condom use in the 6 months prior to interview were considered to have risk behavior. Sexual risk behavior was analyzed separately in contacts with regular and casual partners. In the 6-month preinterview period 92% (108 of 117) of the HIV-infected study population reported sexual contacts, and 30/117 (26%) had at least one unprotected vaginal and/or anal contact. Among 93 persons using condoms, 25% of the heterosexual and 10% of the homosexual participants reported breakage of the condom. The main predictor for unprotected sexual behavior with regular partners was an elevated number of contacts. Predictors for sexual risk behavior with casual partners were the combination of alcohol and sexual encounters and the change of sexual behavior since the epidemic of AIDS. These findings did not differ between persons with hetero-and homosexual behavior. Considering that these contacts may have passed the virus on to the seronegative population, that the probability of unsafe sex increased with the growing number of contacts, and that the number of condom breakages was remarkable, it is imperative that this group be educated and motivated to take the active role in insisting on safer sex practices in each encounter.