Key Points:
- STD rates in U.S. adults dropped in 2024.
- Congenital syphilis in newborns is rising.
- Better screening and treatment are needed.
NEW YORK, Sept. 25, 2025—STD rates in U.S. adults declined in 2024, but syphilis in newborns continued to increase, according to new provisional data from the Centers for Disease Control and Prevention (CDC).
The report released Wednesday showed a third straight year of fewer gonorrhea cases and a second year of declines in chlamydia and the most infectious forms of syphilis in adults. Overall, about 2.2 million cases of chlamydia, gonorrhea, and syphilis were reported last year, a 9% drop from 2023. CDC data shows a decline in chlamydia, gonorrhea, and adult syphilis cases. But congenital syphilis remains a growing concern for infants
Newborn cases continue to rise
Despite the progress among adults, congenital syphilis cases, in which infected mothers pass the disease to their babies, rose again. Nearly 4,000 newborn cases were reported in 2024, an increase of less than 2% from the previous year but still part of a steady upward trend since 2012, when only about 300 cases were recorded.
Congenital syphilis can cause stillbirth, infant death, or lifelong complications, including blindness, deafness, and bone deformities. Health experts stress that no newborn should be affected when the infection is preventable with timely screening and treatment.
“The continued rise in congenital syphilis is a distressing indication that we are not doing enough to protect pregnant women and newborns,” said Elizabeth Finley, interim executive director of the National Coalition of STD Directors.
Declines in adult infections
The CDC recorded about 1.5 million chlamydia cases, 543,000 gonorrhea cases, and more than 190,000 syphilis cases in 2024, all lower than the year before. Cases of primary and secondary syphilis, the most contagious stages of the disease, fell 22%.
Researchers point to several reasons for the overall declines in STD rates in U.S. One factor is that fewer young people are reporting new sexual partners, said Dr. Jeffrey Klausner, an infectious disease researcher at the University of Southern California. Another factor is the increasing use of the antibiotic doxycycline as a preventive treatment. The drug, when taken shortly after sexual activity, has been shown to reduce the risk of syphilis, gonorrhea, and chlamydia.
The practice, known as doxycycline post-exposure prophylaxis, has become more common among gay and bisexual men and transgender women who are at higher risk of STDs, according to health officials.
Gaps in maternal screening
While adult infections declined, the benefits have not carried over to obstetrics wards. A recent CDC study found that only about 80% of pregnant women are screened for syphilis, leaving gaps in detection and treatment. Without early intervention, infected mothers can unknowingly transmit the disease to their babies.
Public health officials say more comprehensive screening, access to prenatal care, and rapid treatment are needed to reverse the trend.
Long-term outlook
In STD rates in U.S. overall remain far above historic levels, even with the recent declines. Experts caution that progress among adults could stall if prevention and treatment strategies are not expanded, particularly for vulnerable groups.
Health agencies are emphasizing increased testing, wider access to preventive medications, and stronger education campaigns as tools to continue lowering adult infection rates and protect infants.
“Every congenital syphilis case represents a failure in prevention,” Finley said. “We have the tools to eliminate it. The challenge is ensuring those tools reach everyone who needs them.”
Visit The Lifesciences Magazine For The Most Recent Information.
