AIDS Patients on HAART More Likely to Have Unsafe Sex, San Francisco Study FindsHighly active antiretroviral therapy (HAART) "increased the risk of acquiring an STD -- an epidemiological marker of unsafe sex -- in people with AIDS," found a study conducted by the San Francisco Department of Public Health and published in the Feb. 10 Lancet. Researchers used a computerized match of people in the San Francisco STD and AIDS registries who were diagnosed with AIDS before 1999 and were alive in November 1995, when HAART became available, or later. They then used a Cox proportional hazards model to determine if "use of antiretroviral therapy was associated with acquiring an STD after AIDS, after adjustment for sex, age, race, HIV-1 risk category and CD4 count at AIDS diagnosis." AIDS reporting in San Francisco is both "passive and active" and "more than 95% complete," according to the study. Researchers used the 1993 CDC definition of AIDS and defined HAART as "use of a protease inhibitor or non-nucleoside reverse transcriptase inhibitor before an STD diagnosis." In capturing STD data, the researchers included people who were reported under California law to the Department of Health as having gonorrhea, chlamydia, syphilis (primary, secondary and early latent) or non-gonococcal urethritis.
Of the 11,516 people found to be living with AIDS in the city, 233 (2%) were diagnosed with an STD after the date of their AIDS diagnosis. Most STDs were in men who have sex with men (213 cases or 91%), with gonorrhea the most common diagnosis (196 cases or 84%). The number of people living with AIDS who acquired an STD "increased over time" from 60 out of 9,043 people in 1995 to 113 of 8,551 people in 1998. The study also found that Americans of "African origin, younger age and higher CD4 count at AIDS diagnosis" were more likely to acquire STDs after AIDS diagnosis.
Confirmation of Other Studies
While researchers noted that "[a]s with any observational study, causality cannot be assumed," they said their findings "strongly suggest" that HAART or "some other factor associated with HIV/AIDS" explains the increase in STDs among people with AIDS. "Several studies," they added, have recently reported an increase in "unsafe sex with the advent of HAART," and this study "confirmed" such findings. HAART may be associated with increased STD incidence because "people on such treatment are likely to feel better and have an increased interest in sex," the study suggests, a theory that "lent support to [the] finding that a higher CD4 count at the time of AIDS diagnosis (a marker of better health) was also associated with increased risk of acquiring an STD after AIDS." The authors note that because most diagnoses were made in men who have sex with men, the results may not be "generalizable to areas in which most AIDS cases are among people in other risk groups" and acknowledge that they "do not know what proportion of sexual partners of people with AIDS are also HIV-1 infected." The authors suggest, "To enhance HIV-1 prevention, more intensive risk-reduction counselling and routine STD screening for people with AIDS is needed" (Scheer et al, Lancet, 2/10).