The Centers for Disease Control and Prevention announced some deeply disconcerting news on Tuesday: Sexually transmitted infection rates have skyrocketed over the last year, particularly among gay and bisexual men. Syphilis transmission rates are especially alarming: The CDC reports a 15.1 percent increase in new infections nationwide since 2013, with a stunning 83 percent of male cases affecting men who have sex with men.
What’s going on here? One obvious explanation could be the rise of PrEP (or Truvada), a daily pill, which, all available data indicate, fully protects against HIV infection. Early studies of PrEP showed no evidence that those who took the drug would stop using condoms. But recent surveys suggest that at least some PrEP users do indeed use condoms less regularly once they’re on the pill. Most notably, a fairly small-scale study in San Francisco found a 30 percent instance in STIs among PrEP users after six months—which rose to a 50 percent after one year.* Just as troublingly, 41 percent of subjects admitted to using condoms less frequently while on PrEP.
The San Francisco study was too small to prove that PrEP is closely correlated to decreased condom use. But combined with the new CDC report, its findings should set off alarm bells. San Francisco is probably the first city in the world where PrEP usage has become normalized within the LGBTQ community. The apparent result: a decline in protected sex and a surge in STIs among the PrEP users. In early studies, when PrEP was novel and scarce, condom use stayed consistent. In newer studies, where PrEP has become widespread, condom use appears to be falling.
Is San Francisco our first preview of a dangerous new PrEP culture, where many gay and bisexual men ignore the risks of STIs once a critical mass of men are on PrEP? That would be the worst-case scenario, and there’s no reason to assume it’s true. But the possibility is worth considering—and, if feasible, forestalling. Nobody wants to be a condom scold, but many gay and bi men seem to have forgotten just how hazardous non-HIV STIs can be. We are already witnessing the rise of antibiotic-resistant gonorrhea, and even run-of-the-mill STIs can be fatal if left untreated. Gonorrhea, syphilis, and chlamydia may not be as scary as HIV. But they remain far too perilous to be shrugged off.
Amid all this minacious data, one bright spot bears mentioning. Even as STI rates rise, HIV infection rates are plummeting in San Francisco, at least in part because of PrEP. The drug is working—but, as the CDC report indicates, it may be causing some collateral damage. Are these growing pains as the LGBTQ adjusts to sex in the PrEP era? Or are they a foreshowing of public health calamities to come? I hope it’s the former. But I’m no longer so sure.
*Correction, Nov. 18, 2015: This post originally misstated that the San Francisco study measured the increase in STIs among participants. It measured the instance of STIs.