Prenatal and Congenital Syphilis Cases Continue Sharp Rise in the United States

Kenny Lin, MD, MPH
Posted on February 5, 2024

Last November, the Centers for Disease Control and Prevention (CDC) reported that the number of individuals with congenital syphilis in the United States had soared 755% over the past decade, peaking at more than 3,700 in 2022. The CDC’s review of that year’s cases revealed that nearly 90% were potentially preventable, resulting from a lack of timely testing and adequate treatment. An analysis of 2017–2019 Medicaid claims in six southern states (Georgia, Kentucky, Louisiana, North Carolina, South Carolina, and Tennessee) found that despite state laws mandating prenatal syphilis screening, actual screening rates ranged from 56% to 91%.

A previous AFP Community Blog post discussed how the diversion of public health personnel and resources during the COVID-19 pandemic had hampered contact-tracing efforts to prevent the spread of syphilis and other sexually transmitted infections (STIs). Since June 2023, syphilis treatment has been affected by a global shortage of injectable benzathine penicillin, leading the CDC to advise prioritizing its use for infections in pregnant patients and babies with congenital syphilis (doxycycline can be used for infections in nonpregnant people).

The U.S. Preventive Services Task Force recommends screening for syphilis in nonpregnant patients who are at increased risk so that those who test positive can be treated to break the chain of infection; however, the number of individuals with syphilis in the United States continues to rise. The CDC’s latest Sexually Transmitted Infections Surveillance Report documented more than 207,000 cases in 2022—a 17% increase over 2021 and the highest number reported since 1950. Few communities were spared; at least one case of congenital syphilis was reported in 47 states and the District of Columbia.

An editorial in the January 2024 issue of AFP reviewed the management of STIs during pregnancy. At a minimum, all pregnant patients should receive screening for syphilis in the first trimester, with repeat screening recommended at 28 weeks and at delivery for patients at high risk or who are living in high-prevalence communities. Clinicians should have a “low threshold of suspicion” for atypical presentations:

Although the classic syphilitic chancre is a single, sharply demarcated, painless ulcer, only 30% of patients have this presentation. Chancres may be hidden (e.g., in the cervix or rectum) or absent. Opt-out screening is essential because a large National Institutes of Health study found that 49% of pregnant women with syphilis from 2012 to 2016 had no identifiable risk factors.

A recent New England Journal of Medicine article reviewed the evaluation and management of neonates with congenital syphilis.

As my colleague Dr. Jennifer Middleton has mentioned in the Blog, the CDC has proposed a novel prevention strategy called doxy-PEP (doxycycline preexposure prophylaxis for syphilis and other STIs) for cisgender men who have sex with men and transgender women who have sex with men with an STI diagnosis in the last year. Unfortunately, a recent trial of doxy-PEP in cisgender women in Kenya who were receiving HIV PrEP found no reduction in STI incidence, although participants’ overall adherence to doxycycline was low.