New provisional data today from the Centers for Disease Control and Prevention (CDC) show signs of progress amid continuing challenges in the fight against sexually transmitted infections (STIs).
The good news is that combined cases of the three most common STIs—chlamydia, gonorrhea, and syphilis—in 2024 were down by 9% from the previous year, marking the third straight year of declines. Reported chlamydia cases fell by 8%, gonorrhea infections by 10%, and primary and secondary syphilis (the most infectious stages of the disease) by 22% compared with 2023, with similar declines seen in men and women. Rates of all three STIs were also down.
But cases of congenital or newborn syphilis, in which the infection is transmitted from mother to child, continue to rise.
Continued increases in newborn syphilis
The declines in STIs follow a decade of increases and failed efforts to stem the tide. From 2011 through 2021, reported STIs rose by 42% in the United States.
The CDC attributes the declines to better awareness of STIs, increased use of newly approved at-home STI tests, better point-of-care tests, and use of doxycycline post-exposure prophylaxis (doxy PEP), which involves taking the antibiotic doxycycline within 72 hours of unprotected sex. The CDC recommends doxy PEP for high-risk groups such as men who have sex with men and transgender women with a recent history of STIs.
But the 2.2 million STIs reported last year still represent a 13% increase from 2015. Furthermore, cases of congenital syphilis rose for the 12th straight year. The nearly 4,000 cases reported in 2024 represent a 2% increase from 2023. Although the increase is smaller than in recent years, cases of congenital syphilis are nearly 700% higher than they were a decade ago.
Congenital syphilis can lead to stillbirth, miscarriage, or neonatal death. Infants who survive but don't receive adequate treatment can develop blindness, deafness, developmental delays, or skeletal abnormalities.
"While the STI epidemic may be turning a corner, we must accelerate progress and stop its most tragic consequences," Brad Stoner, MD, PhD, director of the CDC's Division of STD Prevention, said in an agency press release. "We need to continue our prevention efforts wholeheartedly at federal, state, and local levels."
Lack of timely testing, adequate treatment
Although congenital syphilis is preventable with regular testing and proper treatment of syphilis during pregnancy, the CDC noted in a 2023 Vital Signs report that lack of timely testing and adequate treatment contributes to substantial proportions of cases in all parts of the country and all racial and ethnic groups.
"The continued rising rates of congenital syphilis—a completely preventable condition—are alarming," Lori Tremmel Freeman, CEO of the National Association of County & City Health Officials, said in a press release. Freeman also highlighted the role of public health departments, which have been hit in recent years by job losses and budget cuts, in the progress made against STIs. She said increased federal support is critical for sustaining outreach programs, treatment services, and staff.
"Without local health department staff, there could not be reductions in STI rates, nor hope to reduce congenital syphilis rates," she said.
The CDC said it expects the 2024 STI data to be finalized next year.
