CDC reports small decline in sexually transmitted infections

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For the first time in years, US public health officials are reporting some good news on sexually transmitted infections (STIs).

According to surveillance data released today by the Centers for Disease Control and Prevention (CDC), the number of STIs declined by 1.8% from 2022 to 2023, a sign that the dramatic rise in STI incidence since 2011 might be leveling off. CDC officials welcomed the news.

"I see a glimmer of hope amidst millions of STIs," Jonathan Mermin, MD, MPH, director of CDC’s National Center for HIV, Viral Hepatitis, STD, and TB Prevention, said in a CDC press release. "After nearly two decades of STI increases, the tide is turning."

STI incidence still high

Overall, the number of reported STIs remain high. Over 2.4 million cases of gonorrhea (601,319 cases), syphilis (209,253), and chlamydia (1,648,568) were reported in 2023. That includes 3,882 cases of congenital syphilis, which occurs when mothers pass the infection to their newborn. 

But even a small decline in STIs is a step in the right direction after years of increases. From 2011 to 2021, reported STI cases in the United States rose by 42%. And after a dip in 2021 linked to the COVID-19 pandemic and social distancing measures, STI numbers have continued to climb in recent years.

I see a glimmer of hope amidst millions of STIs.

The decline was driven primarily by a drop in gonorrhea cases, which fell by 7.2% from 2022 to 2023. Gonorrhea rates decreased among both men and women but were most pronounced among women (a 14.1% decrease). Chlamydia rates remained stable, rising by less than 1%.

Although the 209,253 syphilis cases reported in 2023 constitute the most cases reported since 1950, the 1% increase represents progress after several years of double-digit increases. Notably, cases of primary and secondary syphilis, which are the most infectious stages of the disease, fell by 10%, marking the first substantial decline in more than two decades, the CDC said.

The number of congenital syphilis cases reported is the highest since 1992. In addition, 279 congenital syphilis stillbirths and neonatal/infant deaths were reported. But the increase in congenital syphilis (3%) is significantly smaller than in prior years.

The CDC report also shows that wide disparities in STI incidence remain. Almost half (48.2%) of reported cases of chlamydia, gonorrhea, and syphilis in 2023 were among adolescents and young adults ages 15 to 24 years, and nearly one-third (32.4%) were among Black persons. Gay and bisexual men also continue to be disproportionately affected.

Doxy PEP, new at-home tests are helping

The CDC attributes the small decrease in STIs to a number of factors. Among them is the introduction of doxycycline post-exposure prophylaxis (doxy PEP), which involves taking the antibiotic doxycycline within 72 hours after unprotected sex. 

The strategy, which has been found in clinical trials to dramatically reduce the incidence of chlamydia, syphilis, and gonorrhea, is recommended by the CDC for high-risk groups such as men who have sex with men and transgender women with a history of recent STIs. Although there are some concerns about antibiotic resistance, the CDC says it needs to keep expanding the reach of doxy PEP in these groups and conduct more research into whether other groups might benefit.

Other contributing factors include newly authorized at-home tests for gonorrhea, chlamydia, and syphilis and a nationally coordinated response to the syphilis epidemic.

To keep driving incidence down, the CDC says the STI epidemic needs to be prioritized at the federal, state, and local levels, with more investment in robust public health systems and trained workforces who can provide STI services. The agency also calls for making STI services more accessible in local communities and developing new prevention, testing, and treatment options.

We call upon the new Trump administration and Congress to invest in STI prevention programs.

But in a statement, the head of the National Coalition of STD Directors warned that the progress will not continue if federal funding for STI prevention is cut.

"We applaud the progress being made to reduce STIs in America and are cautiously optimistic, but we are concerned these advances will not continue until money is restored to STI prevention that was reduced as part of debt ceiling legislation enacted around the same time as STI numbers started to come down," NCSD Director David Harvey said. "We call upon the new Trump administration and Congress to invest in STI prevention programs in states, cities and territories that have a proven track record of success."

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