Congenital syphilis rises for 12th straight year as U.S. STIs overall decline

Congenital syphilis cases in the United States rose for the 12th straight year in 2024, even as the total number of reported sexually transmitted infections declined for the third consecutive year, according to provisional data from the Centers for Disease Control and Prevention. Nearly 4,000 congenital syphilis cases were reported in 2024, up about 700% since 2015 when just under 500 cases were documented. The year-over-year increase was about 2% from 2023 to 2024.

The broader STI picture remains a challenge. The CDC data show the overall number of STI cases fell 9% in 2024 from 2023, driven by declines in gonorrhea and chlamydia and a roughly 22% drop in primary and secondary syphilis for the second year in a row. Despite these gains, congenital syphilis continues to reflect gaps in prenatal care, access to testing, and timely treatment that public health officials say must be addressed more aggressively.

Dr. Bradley Stoner, the director of CDC’s Division of STD Prevention, said it’s promising that the rate of increase for congenital syphilis is slowing, but that the rising case numbers are still concerning. Congenital syphilis is preventable; syphilis can be cured with treatment, and if it’s treated during pregnancy, that can protect the fetus from becoming infected. But if left untreated, syphilis can be passed on to a fetus during pregnancy or delivery. The infection can damage major organs, including the heart and brain, and can lead to blindness, deafness, and even death. Congenital syphilis can also cause miscarriage and stillbirth.

Stoner noted that reductions in STI services at the state and local levels, as well as social and economic conditions such as poverty and lack of health insurance, have likely contributed to rising rates of syphilis, which in turn led to increasing rates of congenital syphilis. Federal funding for STI prevention has seen drastic cuts since the early 2000s, a period when the number of people living in poverty surged, though it has since declined. While the uninsured rate has fallen since the Affordable Care Act, millions remain uninsured or underinsured. Access to quality care can be uneven, affecting testing and treatment timelines for pregnant people.

Elizabeth Finley, interim executive director of the National Coalition of STD Directors, said part of the problem is that pregnant people’s access to health care or preventive syphilis care may vary. Some may not have consistent prenatal care, and some clinicians may be encountering syphilis cases for the first time. “You get this perfect storm of people who aren’t getting enough prenatal care to begin with for many, many reasons, and then you see providers who haven’t had to identify or test for syphilis in the past,” Finley said. She cited intermittent drug shortages that have impeded rapid treatment and noted that overall STI rates have been rising in recent years. “Any time there are more STI cases in a community—or more cases of any infection—and in this case, syphilis—in a community, you have an increased likelihood that pregnant women will be exposed to it and then that their infants or their fetuses will be exposed to it.”

The CDC noted a few areas of progress in addressing the problem: cases of the two most infectious stages of syphilis, known as primary and secondary syphilis, declined nearly 22% for the second year in a row. Still, Stoner said the public health challenge remains large and that congenital syphilis will continue to be a measure of how well the health system reaches pregnant people with timely prevention and treatment. He expressed guarded optimism that the decrease in other STI categories could foreshadow broader gains if prevention efforts are sustained and expanded.

The agency also highlighted tools that help reduce transmission risk, including self-testing and the antibiotic doxycycline, which can be used within 72 hours after sex to lower the risk of acquiring syphilis, chlamydia, and gonorrhea. “The data do suggest that we may be turning the corner on STIs,” Stoner said. “But the fact that congenital syphilis is still a major problem tells us that we have to accelerate progress to stop the STI epidemic and its most tragic consequences. These are preventable infections, and greater awareness and greater early intervention, I think, will help us get these infections under better control.”

The CDC recommends that pregnant people be tested for syphilis three times during pregnancy, and Stoner encouraged people of reproductive age to get tested and discuss STIs with their partners. Finley acknowledged the progress that public health initiatives have achieved but called for a more coordinated and sustained effort across federal, state, and local agencies to tackle congenital syphilis comprehensively. She added that funding for STI prevention has fallen in recent years and emphasized that the rising congenital syphilis cases occur within a larger context of persistently high STI rates.

Overall, the 2024 data reinforce that congenital syphilis remains a persistent, preventable threat and that narrowing the gaps in prenatal care, testing, and timely treatment will require renewed investment, coordination, and sustained political will across the health system.