THURSDAY, Sept. 25, 2025 (HealthDay News) — Sexually transmitted infections (STIs) declined in U.S. adults last year, but syphilis passed from mothers to newborns continued to climb, new federal data shows.

Tentative numbers from the U.S. Centers for Disease Control and Prevention (CDC) reveal a third straight year of fewer gonorrhea cases and a second consecutive year of declines in adult chlamydia and the most contagious forms of syphilis.

Even so, congenital syphilis — when an infected mother passes the disease to her baby — remains a growing problem.

In 2024, nearly 4,000 cases were reported, a jump from about 300 cases in 2012. Although last year’s increase was less than 2% compared with 2023, health experts stress that no child should ever be born with this infection.

“The continued rise in congenital syphilis is a distressing indication that we are not doing enough to protect pregnant women and newborns,” Elizabeth Finley, interim executive director of the National Coalition of STD Directors, a group representing health department STI leaders, told The Associated Press.

Last year, doctors diagnosed about 1.5 million chlamydia cases, 543,000 gonorrhea cases and more than 190,000 syphilis cases nationwide, according to the CDC. That adds up to more than 2.2 million infections, about 9% fewer than the year before.

Experts say the drop in syphilis among adults may be linked to wider use of doxycycline, an antibiotic taken as a preventive pill after sex.

The CDC reports that early-stage syphilis fell by 22% last year, especially among gay and bisexual men and transgender women who recently had another STI. The disease is most contagious in its early stages.

Still, improvements among adults have not yet reached pregnant women. A recent CDC study showed only 80% of expectant mothers are screened for syphilis.

More information

The Mayo Clinic has more on syphilis.

SOURCE: The Associated Press, Sept. 24, 2025