I was a little surprised by the recent news that HIV transmission “seems to be out of control” among gay men in Europe. That “out of control” quote is what got me — it’s a direct quote from a respected scientific journal, The Lancet Infectious Diseases. But I’m not sure that the journal’s own data justifies such provocative language.
The Lancet Infectious Diseases paper was published Sept. 9 — by coincidence, just two days after the journal BMC Infectious Diseases published another alarming article about HIV among gay men, this time in Belgium. That article noted that young gay men in Belgium showed high rates of unprotected sex and reinfection among one another: to put it plainly, the young HIV-positive men in the nine-year study were constantly hooking up with each other — in an ever-widening circle — without reliably using condoms.
The data sounds alarming, yes, but is it right? HIV studies are notoriously difficult to conduct because of the highly variable time between infection and diagnosis. You can contract HIV after a one-night stand and discover it a few weeks later when you suspect something is wrong. Or you contract HIV after having sex with a long-term partner and then find out years later, only after you show symptoms of AIDS. Both of the new studies were designed primarily to help understand this methodological problem, not to measure HIV rates directly.
And in fact the Lancet Infectious Diseases study did not find that HIV transmission increased among *any* population, including gay men. Instead, the Lancet authors used statistical analysis to estimate HIV transmission rates based on a reference population of 298 people in France between 1996 and 2006. The statistical analysis concluded that transmission rates had declined in every population that was studied: straight women, straight men, injection-drug users, and also gay men (or “MSM,” in the grating abbreviation used by epidemiologists; somehow it stands for men who have sex with other men).
So how did The Lancet Infectious Diseases conclude that HIV transmission among gay men “seems to be out of control”? The rate of decline in HIV transmission among gays was significantly lower than the rate of decline among other populations. Between 2% and 3% of gay men are thought to have contracted HIV in France during the period studied, compared with just 1% of the population at large. True, that means openly gay men are two or three times as likely to contract HIV — but does it really mean gays are “out of control”?
The BMC Infectious Diseases paper was also misunderstood. It was based on a Belgian population of approximately 500 patients who had proven resistant to standard HIV therapies; the patients had presented themselves at an AIDS clinic in Ghent. Among this group, unprotected sex between men turned out to be the main mode of HIV transmission; 59% of those infected said they believed they had gotten HIV from having sex with another man. That’s not a surprising figure. Since before HIV was even discovered, we have known that gay men pass the AIDS virus among ourselves more than any other population. We have also paid the highest price.
But the Belgian study concluded that HIV transmission among young gay men has grown based on a tiny sub-sample of just 57 “MSMs.” They were a cluster of young gays who had, improbably, found the nightlife in Ghent intoxicating: they had more or less all slept with one another, sharing not only HIV but also syphilis and chlamydia. The BMC paper recommended more outreach to this population, but the data doesn’t justify the headlines. Instead it proves that HIV remains a problem among gay men, one that requires steady intervention, not outrageous language.