Knowing HIV status for prevention seen on rise

SAN FRANCISCO, May 2 (Reuters) Knowing a partner's HIV status before sex is a growing prevention method among young gay men, although risky behavior likely to transmit the virus is on the rise, according to two new US studies.

The studies, which used virtually the same method to look at the prevalence and risk of HIV infection among gay men in San Francisco, also found that more effective therapies to fight the virus may be prompting uninfected men to use fewer protections when engaging in sex.

Sandra Schwarcz, an epidemiologist at the San Francisco Department of Public Health, said the studies point to a need to better understand the growing practice of choosing a sexual partner based on their HIV status -- something researchers termed serosorting.

''The behaviors of gay men with committed partners were less risky than (those with) partners they were not committed to,'' she said in a telephone interview today. ''This has been a change.'' In Schwarcz's study, researchers questioned a group of men who knew they were infected with HIV and another group who were either HIV negative or did not know their status to see what activities might be spurring risky behavior.

Use of drugs such as methamphetamines and the fact that many men not infected with HIV were now less careful because of more effective HIV treatments were some of the reasons researchers cited for the increase in unprotected sex.

More than 25 million people have died of AIDS since the incurable disease was first recognized in 1981 and about 40 million now live with HIV, the virus that causes AIDS.

While the studies looked at gay men only in San Francisco, researchers said the results were a likely indicator of what is happening in other cities across the United States.

Dennis Osmond, a researcher at the University of California, San Francisco, said his study found that the number of gay men engaging in unprotected anal sex with a partner of a different HIV or unknown status rose from about 9 per cent in 1997 to nearly 15 per cent in 2002.

At the same time, however, there was an increasing trend among gay men to choose sexual partners with the same HIV status.

''When you are practicing it, it is a way of reducing risk,'' he said in an interview. ''It appears it is a trend that has been growing in the last decade, especially among young men.'' Both studies found that about a quarter of the gay men in San Francisco were HIV positive.

REUTERS SYU ND0910