High-risk sex studied in women, men.

High-risk sex studied in women, men

With sexual contact a principal conduit of AIDS infection, studies of sexual practices are important in predicting how far the viral disease may move through the population. Last week, scientists reported on two such behavioral studies--among the female sex partners of infected men and among male homosexuals in a low-incidence area. While the first study found male-to-female transmission of the AIDS virus, the second concludes that widespread "unsafe' sex persists among male homosexuals living in areas lacking large numbers of AIDS cases.

In a study of 97 female partners of 93 men known to be infected with the AIDS virus, an overall 23 percent of the women had acquired the AIDS virus, say researchers at the University of California at Berkeley and at the health departments of San Francisco and California. The source of the male partner's infection appeared to be important: 21 to 25 percent of the female partners of AIDS-infected bisexual men, hemophiliacs and those infected through transfusions had themselves been infected, compared with 42 percent of the female partners of intravenous drug users. Although the majority of women were partners of men who had developed AIDS or AIDS-related complex, there was no association between the men's disease status and transmission of the virus, say the authors.

Likelihood of infection increases with the total number of sexual exposures to the infected male partner, as well as with the practice of anal intercourse with the infected partner, Berkeley's Nancy Padian told SCIENCE NEWS. Padian and her coauthors report in the Aug. 14 JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION (JAMA) that infected women were nearly five times more likely then uninfected women "to have had more than 100 sexual exposures with their infected partner.' Also, those who practiced anal intercourse were more than twice as likely to be among the infected group. But the scientists found no relationship to the total number of sexual partners, the woman's history of sexually transmitted diseases or oral sex.

Padian says the women in the study are closer to the "average, middle-class' person than the subjects of some AIDS studies. She emphasizes that "you simply cannot generalize from this group to the general population,' because the male partners were known carriers of the virus.

Despite general awareness about AIDS, those not directly confronted with victims of the disease have been slow to change risky behavior, says New Mexico's state epidemiologist, Harry F. Hull of Santa Fe. With others in the state's health department and at the Centers for Disease Control in Atlanta, Hull reports in the Aug. 14 JAMA on a study testing visitors to New Mexico's sexually transmitted disease clinics between mid-1985 and January 1986. Tests showed that 14 percent of the homosexual and bisexual men studied were infected with the AIDS virus, a figure comparable to that found in San Francisco in 1980. Hill says the incidence in New Mexico has since risen to 20 percent, evidence that AIDS continues to spread despite educational efforts.

"Everywhere in the country, we're seeing denial,' says Hull. "I hope [low-incidence areas like New Mexico, with less than 4 percent the rate reported in New York City] can learn the bitter lessons vicariously.'