What's Going on With Americans and Syphilis?

The U.S. has a big syphilis problem on its hands. New data from the Centers for Disease Control and Prevention shows that reported cases of the sexually transmitted infection once again climbed in 2022, reaching a total not seen in over 70 years. In slightly better news, reported cases of gonorrhea have taken a slight downturn, while chlamydia cases have stayed level.

The numbers come from the CDC’s latest STI Surveillance Report, which details the annual recorded incidence of chlamydia, gonorrhea, and syphilis, three major STIs that doctors and local health departments are obligated to track and report to the CDC (other STIs like HIV or hepatitis B are tracked as well, but their numbers are reported separately). All of these figures are known to be an underestimate of how often these infections truly occur, since STIs don’t always cause symptoms, at least at first, and go undiagnosed as a result.

In 2022, there were more than 2.5 million reported cases of the three overall, a smidge below the 2.53 million cases reported the prior year. The incidence of chlamydia, the most commonly reported STI, has stayed flat following a recent decline, with around 1.64 million cases in both 2021 and 2022. Gonorrhea saw a noticeable decrease from the over 700,000 cases in 2021 to around 650,000 cases in 2022—the first decline in a decade.

But there were more than 200,000 reported cases of syphilis in 2022, well above the nearly 174,000 in 2021. This tally includes 3,755 cases of congenital syphilis, which led to 231 stillbirths and 51 infant deaths. According to the CDC, the caseload of syphilis in 2022 is the highest seen since 1950.

“The STI field has reached a tipping point. We have long known that these infections are common, but we have not faced such severe effects of syphilis in decades,” wrote Laura Bachmann, acting director of the CDC’s Division of STD Prevention, in a statement announcing the report.

The continued rise in congenital syphilis is especially disheartening, given that it’s almost completely avoidable. The CDC estimates that nearly 9 out of 10 cases in 2022 could have been prevented with proper prenatal screening and prompt antibiotic treatment for pregnant mothers. Instead, two of five people who had a child born with syphilis in 2022 are thought to have received no prenatal care at all. The progress against syphilis in general has also taken a remarkable backslide since the early 2000s, when cases had reached an all-time low.

For years, the U.S. has seen growing case numbers of all three STIs. So the recent decline of reported chlamydia and now gonorrhea cases might suggest a positive development. But the CDC notes that the covid-19 pandemic likely disrupted some people’s access to STI testing and hampered surveillance efforts. So it’s possible that these numbers don’t represent a true decline in infections. The CDC will be taking a close look at the 2023 data to better assess these trends. In the meantime, the clear jump in syphilis cases is reason enough to improve STI education, prevention, and treatment strategies on a national level, according to the health agency.

“There are no shortcuts, and we have to meet people where they are. Some people face tremendous barriers to STI prevention and health services,” Bachmann said. “So, the most important work is often outside the clinic, whether it be reaching out to communities with testing, interviewing patients to offer services to their partners, or delivering treatment directly to someone.”