It seems like every year we get a new alarming stats to set on top of last year's alarming new stats—we've got eight years' worth of alarming stats to pour over now. And the news for gay and bisexual men isn't good:

U.S. syphilis rates rose for a seventh year in 2007, driven by gay and bisexual men, while chlamydia reached record numbers and gonorrhea remained at alarming levels—especially among blacks, health officials said on Tuesday.


[Syphilis] rates rose 15 percent from 2006. Syphilis rates dropped by 90 percent in the 1990s to a record low level in 2000, and officials thought it might disappear as a public health threat before its resurgence this decade.

Syphilis has increased each year since 2000—its rate is up 81 percent—with gay and bisexual men representing 65 percent of cases, the CDC said.

Douglas said many cases are occurring in HIV-positive men who are choosing other HIV-positive men as sexual partners. "Within that relationship, they are less concerned about the transmission of other conditions. They're not using condoms. They believe that their partner already has got the worst they can get—they've got an HIV infection," he said.

So... gay and bi men who opt to have sex with other men who share their serostatus—poz guys with poz guys, neg guys with neg guys—because it allows them to skip the condoms are fueling a nearly decade-long spike in syphilis rates. I've praised serosorting as an effective method of HIV prevention—here's a good primer on the practice from the SF AIDS Foundation—and it is. But its been clear for years now that serosorting carries other risks. Serosorting is only an effective HIV-infection prevention strategy—particularly for neg guys—if people are 1. honest and 2. aware of their HIV-statuses. (Lots of men are infected and don't know it; some were infected too recently for their last HIV test to detect their infection.) It is extremely foolish for a negative guy—particularly one seeking multiple, casual, or anonymous sex partners—to put a great deal of faith in a stranger's professed HIV-status; a poz guy can know for sure he's positive but a negative guy can never really know for certain that he's negative. Some guys who are positive don't know, some are in denial, and men will lie. (And by stigmatizing HIV+ guys, it has to be said, HIV- guys help create a climate that encourages other men to either not know their status or to hide it.)

But even when it works as planned—neg guys skipping condoms with neg guys, poz guys skipping condoms with poz guys—serosorting obviously encourages the spread of other sexually transmitted infections. Many of these infections—like syphilis—are treatable. Since some men have syphilis without realizing it, because they didn't notice the initial symptoms, and because the consequences of untreated syphilis are pretty dire, anyone who has multiple sex partners—serosorting or not, condoms or not—should get regular STI screenings.

And now my annual Cassandra moment: Yeah, serosorting may be effective for preventing the spread of HIV. It can make it possible for two neg guys to have sex without condoms without risking HIV infection (provided both guys are actually negative), and it can make it possible for two poz guys to have sex without condoms without spreading HIV. But serosorting does nothing to protect gay men from other STIs. Rational people can conclude that those other STIs are no big deal and that if they serosort for HIV and seek treatment for the treatable STIs and put up with the untreatable ones, they're in the clear medically and morally.

But the emergence of HIV should have made one thing very clear: a new STI can burst onto the scene and kill you and all of your friends. So, yeah, serosorting can allow guys to have unprotected sex without having to worry about the potentially fatal sexually transmitted infection we do know about. But what if there's a new fatal STI out there that we don't know about?