Syphilis Is Surging, and U.S. Public Health Officials Aren't Sure Why

It's hard to miss "SYPHILIS EXPLOSION" ads that prominently feature those capitalized words before a fiery red erupting volcano. They were plastered acrossBART stations in the Bay Area and billboards in Los Angeles late last year courtesy of the AIDS Healthcare Foundation, which says the campaign has already appeared in or is heading to Cleveland, Columbus, Baton Rouge, Brooklyn and other cities.
Syphilis, which can cause serious health problems if untreated, is on a troubling upswing across the United States. The rate of primary and secondary syphilis infections fell by nearly 90 percent between 1990 and 2000, but has increased most years since, according to a Centers for Disease Control and Prevention report analyzing public health data through 2013. This recent wave of syphilis is mostly a problem confronting gay men—or, to use the broader medical term, men who have sex with men. Between 2000 and 2004 alone, the CDC reports that the estimated proportion of primary and secondary syphilis infections attributable to men having sex with men rose dramatically, from 7 percent to 64 percent.
Nationwide, the CDC reports that primary and secondary syphilis rates increased by 10 percent between 2012 and 2013—an infection rate more than twice as high as figures from 2001. The Atlanta, Baltimore, Detroit, Los Angles, Miami, Orlando, Portland, San Antonio, San Diego and San Francisco metro areas have some of the highest syphilis rates, according to the CDC.

Advertisements warning of an increase in syphilis infections have appeared in recent months in major U.S. metro areas. (Courtesy AHF)


In the San Francisco Bay area, reported cases rose from 438 in 2009 to 814 in 2013. In Washington, D.C., Dr. Raymond C. Martins, senior director of clinical education at Whitman-Walker Health,says that the clinic saw a 32 percent increase in syphilis cases among patients between 2011 and 2014. And in recent months, at least 15 cases of ocular syphilis, a serious complication of the disease that can cause blindness, have been reported in California and Washington state, according to an alert released earlier this month by the CDC. Most of these infections have occurred among HIV-positive men who have sex with men.
Syphilis, which can spread through sexual contact and also from a pregnant woman to her fetus, is easy to treat: antibiotics typically do the trick. But it is hard to detect and easy to spread because the early-stage symptom, a sore called a chancre, typically takes about three weeks to appear. Symptoms can also later disappear for a time, giving infected persons the false impression that they are clear of the disease. It remains a much largerproblem in poorer countries, causing hundreds of thousands of pregnancy complications annually to mothers with the disease. But its upswing in the United States has public health officials worried.
A decline in the use of condoms is one obvious culprit. The percentage of men who have sex with men estimated to have had unprotected anal sex within the previous 12 months rose from 48 percent in 2005 to 57 percent in 2011, according to the CDC. But while it is clear that syphilis is spreading fast, and that it is spreading especially among men having sex with men, public health and medical experts still don't know the answers to some really basic and important questions.
"We haven't really seen enough data to help us understand why there is this increase," says Jay Laudato, executive director of the Callen-Lorde Community Health Center, which provides health care to New York's LGBT communities.
One theory is that the disease may be spreading in part because HIV-positive gay men are choosing to have unprotected sex with HIV-positive partners, a phenomenon called seroadaptation or serosorting. In one important respect, this is a laudable risk-reduction strategy that can protect exposing HIV-negative people to HIV. But it can also put HIV-positive men at greater risk for STIs like syphilis.
"There are a number of people who are on networks disclosing their HIV status, which we support. And for those people, they are choosing to have condomless sex if both partners know that they have HIV," says Laudato. "That's something that's been happening for quite some time. And it absolutely does lead to increased STIs."