New cases of HIV in San Francisco dipped nearly 10% in the last five years, marking the first drop in infections since the late 1980s, according to preliminary estimates from the city's Department of Public Health.
"It looks like we're on the waning side" of this wave in the epidemic, said department epidemiologist Willi McFarland. But, he said, "Certainly, the job is not done."
The findings, issued this week by a city often considered a bellwether for HIV trends among gay males, came as somewhat of a surprise.
The change in absolute numbers, from an estimated 1,084 cases in 2001 to 976 in 2006, isn't huge, but San Francisco's gay male population increased 25% in that period, said McFarland. Also, increases in syphilis -- often transmitted through unprotected sex -- and studies showing high-risk behavior among young men seemed to predict a resurgence in HIV.
The department had been expecting a rise of up to 33%, McFarland said.
"This is great news; we're making progress," said Mark Cloutier, executive director of the San Francisco AIDS Foundation. "But I think it is both bad planning and bad public policy to look toward the future based on a [short-term] trend. We don't know how long this will last."
He and others emphasized that the estimated decrease was moderate, especially compared with the plunge in cases two decades ago. Furthermore, nonprofit workers and health officials are still worried about high HIV/AIDS rates for black men who have sex with men.
The overall HIV dip seems to run counter to the national pattern. In 2004, the rate of new diagnoses among gay and bisexual men of all races, stable for the preceding three years, rose 8%, according to the U.S. Centers for Disease Control and Prevention. Los Angeles County officials said they do not have estimates of new HIV cases.
Although doctors and laboratories have been required to report HIV cases to the state since 2002, the reporting system, based on assigning codes to patients rather than identifying them by name, is believed to be seriously flawed. Seeking a more accurate figure, the San Francisco health department looked at a variety of sources, including studies, reports from doctors' offices and test sites, and data from other health agencies.
The reasons for the apparent decline in San Francisco are unknown, but many are pointing to a relatively new community-based effort known as "sero-sorting" -- a practice of engaging in sexual activity only with partners sharing the same HIV status. The practice can be informal but is becoming more common on gay-oriented websites such as Poz.com, which offers personal ads for the HIV-positive.
When San Francisco resident Lee Jewell, 45, tested HIV positive in 1986, he said, one of his worst fears became infecting someone else.
"I almost died from this disease," Jewell said. "Going through that plus the medication -- it's something that I wouldn't want to wish upon anyone."
He said he found it easier to date other HIV-positive men.
Some AIDS activists said the old approaches to prevention weren't working. The message the nonprofits were sending -- "Don't ever, ever have unprotected sex" -- was met with a certain amount of fatigue in the community, said Robert McMullen, director of the nonprofit Stop AIDS Project.
"We are now telling people, 'Whatever you do, you have to have an effective strategy,' " McMullen said. "That strategy would include things such as sero-sorting."
Medications that substantially reduce viral load, as well as needle-exchange programs targeting drug users also at risk for the disease, could also help explain the decrease, McMullen said.
The story of AIDS in San Francisco has been marked by fluctuations between feelings of hope and doom. In the early 1980s, new HIV infections shot up to a peak of 6,000 to 8,000 per year.
The number of new infections then plunged but climbed again in the mid-1990s, when new protease inhibitors became available. These medications allowed HIV-positive people to live longer and healthier lives but also caused people to relax their safe-sex practices.
"From 1995 to 2001, there was a sentiment of optimism," said McFarland. "Several thousand men who would have died actually lived, and not only were they living, they were living better."
A report issued by the city health department in 2001 proved sobering. HIV infections had nearly doubled since the early 1990s, to more than 1,000 cases annually.
This time, health officials are determined not to take progress for granted.
Now, "People are taking responsibility and are taking care of this," said Tracey Packer, director of HIV prevention for the department. "Our communities and agencies are having an impact."
Rates of early stage syphilis also are declining after a period of alarming increase. According to a departmental report, syphilis infections in San Francisco declined 23% from 2004 to 2005, marking the first decrease since a rapid rise that began in 1999.
One possible downside to the apparent drop in HIV cases: If cases dip below certain thresholds, San Francisco could lose federal dollars for prevention and treatment, and city funds could be shifted elsewhere.