August 14, 2003
Worldwide, sexual contact is the major mode of HIV transmission among adults. Citing a lack of data on sexual behavior in HIV-infected individuals on potent antiretroviral therapy, the authors evaluated the sexual behavior of individuals in the Swiss HIV Cohort Study. In particular, they looked for associations between unsafe sex and optimal viral suppression.
On April 1, 2000, researchers introduced a new questionnaire into the SHCS, a prospective cohort study of HIV-infected individuals 16 and older. The cross-sectional study included all SHCS participants who responded to the new questionnaire for the first time within 12 months of its introduction. Answers to survey questions -- on protected or unprotected sexual intercourse, type of partnership (stable or occasional), known or unknown serostatus of a stable partner, and whether patients lived alone, with relatives or partners, or in institutions -- were voluntary and anonymous.
The scientists gathered clinical and demographic information prospectively within the framework of the SHCS. They measured viral load using the Roche Amplicor Monitor assay, with the modification for ultrasensitive detection. They defined optimal viral suppression as plasma HIV-1 RNA levels of <50 copies/mL at every cohort visit during the 12 months preceding the date of completing the sexual behavior questionnaire.
Of the 4,948 individuals registered with SHCS on April 1, 2000, 4,723 (95 percent) responded to the sexual behavior questionnaire. Fifty-five percent of respondents had a stable partnership and 19 percent had occasional partners during the previous 6 months. Six percent had both types of partners. Eighty-two percent of subjects with stable partners reported intercourse, and 76 percent of those said they always used condoms. Of individuals with occasional partners, 87 percent reported sexual intercourse; 86 percent of those said they always used condoms.
"Overall," the authors wrote, "12 percent of the individuals reported unsafe sex, 81 percent denied unsafe sex, and the remaining 7 percent neither reported nor denied unsafe sex. Of those individuals who responded, 78 percent received antiretroviral therapy, and 25 percent had optimal viral suppression with viral loads of <50 copies/mL during the preceding 12 months.
"In multivariate analysis," they continued, "reported unsafe sex was not associated with optimal viral suppression, antiretroviral therapy, diagnosis of an AIDS-defining disease, or education. However, reported unsafe sex was associated with gender, age, ethnicity, HIV transmission group, HIV status of the stable partner, having occasional partners, and living alone."
The researchers found that individuals with HIV-infected stable partners, from ethnic groups other than white, and those with occasional partners were more likely to report unsafe sex. Males, individuals 41 or older, and subjects living alone were less likely to report unsafe sex.
"In conclusion," the researchers wrote, "the present study underlines the importance of epidemiologic data on sexual behavior in HIV-infected populations. In the SHCS, 4 of 5 HIV-infected individuals report safer sexual behavior with their partners. Individuals receiving potent antiretroviral therapy and those with optimal viral suppression do not seem more likely to engage in unsafe sex. However, unsafe sex is more likely in some subgroups of individuals with HIV infection. Sexual health programs targeting these subgroups should complement programs aimed at the general population."
Journal of Acquired Immune Deficiency Syndromes
08.01.03; Vol. 33; No. 4: P. 494-499; Katja Wolf; James Young; Martin Rickenbach; Pietro Vernazza; Markus Flepp; Hansjakob Furrer; Enos Bernasconi; Bernard Hirschel; Amalio Telenti; Rainer Weber; Heiner C. Bucher; the Swiss HIV Cohort Study