San Francisco Data Shows HIV Rates Still Rising, Experts Say.

The rate of new HIV infections among gay and bisexual men in San Francisco is continuing to rise, a panel of experts said January 24. The group of epidemiologists, city health officials and AIDS prevention experts convened in a special "consensus meeting" estimated that 2.2 percent of gay and bisexual men who don't inject drugs and 4.6 percent of gay/bisexual injection drug users will become newly infected this year.

If correct that translates to 892 new seroconversions in San Francisco, more than double the estimate reached at the last consensus meeting in 1997 and a marked increase over last year's interim estimate of 716 new infections per year. And--contrary to popular stereotypes--the data the scientists reviewed consistently showed that men over age 25 were more likely to seroconvert than those under 25.

The experts estimated annual seroconversions among male-to-female transgendered individuals at 7.8 percent, or 152. Time constraints prevented the group from evaluating data on heterosexuals, including heterosexual injection drug users; a second meeting covering those estimates will take place in February.

The current report is in draft form only and will be finalized after a two week public comment period. Still, Mike Shriver, AIDS advisor to San Francisco Mayor Willie Brown and a longtime AIDS activist, termed the data discussed at the meeting "frightening."

The new estimates, extrapolated from several studies that measured seroconversion rates in various samples of the city's gay/bi male population, were hashed out over nearly five hours January 19. Because last year's announcement proved controversial--in part because it hit the press before city officials expected, producing a jumble of sometimes inconsistent statements-Shriver took the unusual step of inviting four journalists to observe the meeting. All discussions were on the record, but the journalists--this reporter and staff reporters from the San Francisco Chronicle, Bat Area Reporter and San Francisco Frontiers--were asked not to publish the numbers until they were released for public comment January 24.

All involved acknowledged that the process is imperfect and that the figures are estimates, not hard numbers. HIV is not a reportable condition in California and the ideal research design--large "population-based" studies--is expensive, cumbersome and thus fairly rare. So the scientists had to try to review, interpret and synthesize a variety of studies looking at specific groups of men who don't necessarily constitute a representative cross-section of the city's gay and bisexual population--a job rather like trying to assemble a jigsaw puzzle with many of the pieces missing.

Two University of California San Francisco researchers, Susan Buchbinder and Cynthia Gomez, presented new, unpublished data for the group to consider. Buchbinder discussed results from two AIDS prevention studies, a behavioral intervention study and vaccine study, and compared them to the numbers from two roughly comparable studies done in the early nineties. All involved H1Ynegative men who have anal sex and are thus at relatively high risk for HIV infection.

The men in the new studies had a combined seroconversion rate of 4.2 percent per year, compared to 2.2 percent and 2.7 percent in the earlier research. Nine percent reported having unprotected receptive anal sex with partners they knew to be HIV-positive--about triple the previous rate-while an even larger percentage had unprotected receptive anal sex with partners of unknown status.

Optimism about improvements in HIV treatment may be contributing to the increase in risky behavior. 13 percent of the men agreed that they are "less concerned about having sex without a condom" due to the existence of combination anti-HIV treatments, while 21 percent said that treatment reduces a person's infectivity.

Gomez discussed data from the Seropositive Urban Men's Study, which looked at HIV positive gay and bisexual men in San Francisco and New York. Most of the men's sexual partners were of unknown HIV status, Gomez said, noting that researchers found "no difference" in results from the two cities. And--in a number that mirrored Buchbinder's findings--nine percent said that they had had unprotected insertive anal sex in the last 90 days with partners they knew to be HIV negative.

"That's the data that kept me up that night," Shriver said.

The most optimistic numbers came from the San Francisco Young Men's Health Study, which since 1992 has tracked a large group of gay/bi men who were under age 30 when it began, which reported a seroconversion rate of 1.8 percent per year.

Though most of the studies evaluated showed annual new infection rates of four percent or higher, the group chose to err on the side of being conservative. The comments from most of the researchers indicated they thought the 2.2 percent per year figure is an underestimate.