Fewer Americans Are Now Diagnosed with This

Medical researchers announced (mostly) good news on Saturday: HIV infection diagnoses went down by a third for Americans as a whole over the course of a decade. At the beginning of the study period, in 2002, doctors were diagnosing about 24 out of every 100,000 patients with HIV. By 2011, that rate was down to an encouraging 16 diagnoses per 100,000 patients. The overall decline also holds true, according to the BBC, for "men, women, whites, blacks, Hispanics, heterosexuals, injection drug users and most age groups." The only groups that showed an increase? Gay and bisexual men ages 13 to 24, as well as those over 45.

It's important to note that a drop in diagnoses doesn't necessarily mean a drop in overall HIV cases. One theory the researchers have for the overall drop is a "ceiling effect." In that case, most patients who have carried the virus for months or years have already been diagnosed, leaving only newer cases to be recorded without a drop in actual infection rate. (Indeed, the percentage of adults ever tester for HIV rose from 37 percent in 2000 to 45 percent in 2010.) More optimistically, the drop could be due to fewer people getting infected in the first place – although the study's authors are hesitant to cite any one reason, since there are so many possibilities.

The reason for higher diagnosis rates in gay and bisexual men, on the other hand, leaves less to speculation. The authors of the study believe that those new cases are on the whole due to less condom use among men too young to remember the ravages of the AIDS epidemic. "It's been more than 30 years since the first cases were reported," co-author Amy Lansky said. "It's harder to maintain that sense of urgency." The authors of the study estimate that about 16 percent of HIV-positive Americans don't even realize they have the virus. And in a population with higher rates of HIV infection, safe sex is all the more important, even in an age when HIV isn't the death sentence it once was.

Still, HIV-prevention programs – including sterile-needle distribution, increased testing, and better awareness – at least seem to have helped infection rates on the whole. And the study's findings give doctors, activists, and other public-health advocates an idea of where to concentrate their efforts. As it stands, the U.S. is still in line with the global drop in AIDS rates. Do your part to help: when you're having awesomely safe sex, be sure to use an awesomely safe condom.