Los Angeles and San Francisco have yet to see the boom in HIV rates that health officials have been fearing ever since the two cities had syphilis outbreaks among gay and bisexual men earlier this decade.
Health officials believed the syphilis outbreaks indicated that many gay and bisexual men were abandoning safe-sex practices and that a corresponding surge in HIV cases would soon follow.
But large jumps in HIV did not follow. In San Francisco, only 1.9 percent of gay and bisexual men had the AIDS virus in 1998. Although that rate nearly doubled to 3.9 percent a year later, it dropped to 2.4 percent by 2002, the Centers for Disease Control and Prevention said Thursday.
The CDC explained the findings by saying that only a small number of people overall were infected with syphilis and that in both cities, more than half of the men newly infected with syphilis already had HIV.
Yet the government warned that if the syphilis outbreaks continue, health officials still could see a rise in HIV among gay and bisexual men.
Syphilis cases jumped among gay and bisexual men in San Francisco from just four in 1998 to 260 in 2002. In Los Angeles, health officials handled 67 new cases of syphilis in 2000. That shot up to 299 in 2002.
