Prevalence of Kaposi’s Sarcoma Virus Has Remained Stable Throughout AIDS Epidemic, Study Shows
Kaposi sarcoma-associated herpes virus, a virus linked to Kaposi's sarcoma, was present in nearly 25% of gay men in San Francisco several years before the region saw its first major outbreak of HIV, according to a study published in today's issue of the Journal of the American Medical Association, the San Francisco Chronicle reports. The findings "upset the notion" that outbreaks of Kaposi's sarcoma during the early years of the AIDS epidemic represented "a parallel epidemic of a new disease." KS, a skin disease that has been linked to lymph-related disorders and a rare cancer, is not necessarily fatal and was especially prevalent among HIV-positive gay men during the early years of the AIDS epidemic (Russell, San Francisco Chronicle, 1/9). Studies have suggested that KSHV "evolved concurrently with" HIV and that contact with an HIV-positive partner or a partner with KS "is associated with KSHV infection, implying the HIV epidemic may have been a major factor in a KSHV epidemic," the study says. But the report states that during the first six months of 1978, KSHV prevalence among homosexual and bisexual men of the San Francisco City Clinic Cohort was 24.9%, while only 1.8% of men were infected with HIV. KSHV prevalence among all study subjects was 28.4% between 1978 and 1980, 29.6% between 1984 and 1985 and 26.4% between 1995 and 1996. However, HIV infection declined from 49.5% of participants between 1984 and 1985 to 17.6% between 1992 and 1993.
The study authors conclude that KSHV was "highly prevalent in 1978" when HIV infection was still at low levels and that the prevalence of KSHV remained "relatively stable from 1978 to 1996." Although KSHV is "strongly associated with HIV," the reductions in unprotected anal intercourse that led to a decline of HIV infection were not accompanied by a decrease in KSHV infection (Osmond et al., JAMA, 1/9). The study states that the outbreak of KS during the early years of HIV probably occurred because HIV weakened the immune system of men who already were infected with KSHV. In addition, the findings suggest that KSHV is not transmitted through anal intercourse, but may be transmitted via oral sex, a practice that increased during the study period. The study also states that many gay men in San Francisco may still have KSHV that may be "held in check" because of lower HIV infection rates and antiretroviral drugs that boost the immune system (San Francisco Chronicle, 1/9).