STD rates dip in 2024, but congenital syphilis in newborns rises, CDC data show

U.S. sexually transmitted disease rates fell again in 2024, according to provisional data from the Centers for Disease Control and Prevention posted Wednesday. The year marked a third consecutive decline in gonorrhea cases and the second consecutive year of fewer adult infections of chlamydia and the most infectious forms of syphilis, even as congenital syphilis in newborns continued to rise. Overall, more than 2.2 million cases were diagnosed last year: about 1.5 million chlamydia, 543,000 gonorrhea, and more than 190,000 syphilis cases. The total represented roughly a 9% drop from 2023. But congenital syphilis infections, which occur when an infected mother transmits the disease to her baby, rose to nearly 4,000 in 2024. While the 2024 increase was less steep than in prior years — cases were up by less than 2% from 2023 — health experts say no level of congenital syphilis is acceptable.

Cases of primary and secondary syphilis, the disease's most infectious stages, fell 22% last year, the CDC reported. Health experts say the broad declines in adult infections are linked in part to changes in sexual behavior among younger people and, in some groups, to preventive practices. The data also suggest that the improvement in some populations has not yet translated to obstetric settings: only about 80% of pregnant women are screened for syphilis, according to a recent CDC study. In addition, the trend in adult syphilis has been influenced by the growing use of the antibiotic doxycycline as a morning-after pill, specifically for gay and bisexual men and transgender women who recently had an STD diagnosis, the CDC notes.

Despite declines in adult infections, congenital syphilis remains a troubling anomaly in obstetric care. Elizabeth Finley, interim executive director of the National Coalition of STD Directors, called the rise in congenital syphilis a distressing indication that more must be done to protect pregnant women and newborns. “The continued rise in congenital syphilis is a distressing indication that we are not doing enough to protect pregnant women and newborns,” she said.

Congenital syphilis can cause death or lifelong health problems, including deafness, blindness and bone malformations. Health officials say the condition reflects gaps in prenatal screening and access to care, underscoring the need to ensure all pregnant people receive timely testing and treatment. While declines in adult infections are encouraging, experts caution that progress must be mirrored in maternal health to prevent the preventable burden on newborns.