Rise in congenital syphilis highlights pregnancy screening gaps

- Kenny Lin, MD, MPH

Last month, the Centers for Disease Control and Prevention (CDC) announced that the number of reported cases of congenital syphilis in the U.S. rose from 362 in 2013 to 918 in 2017, paralleling increases in syphilis infections in reproductive-age women during this time period. From 2016 to 2017, congenital syphilis cases rose from 16 to 23 per 100,000 live births. Although two-thirds of affected infants have no symptoms at birth, congenital syphilis is associated with increased neonatal mortality and a variety of early (through 48 months of age) and late complications, detailed in a previous AFP article.

The first line of prevention against congenital syphilis is screening for syphilis in all pregnant women at the first prenatal visit, a well-established standard of care that the U.S. Preventive Services Task Force (USPSTF) recently reaffirmed. Although some cases occur in infants whose mothers receive no prenatal care, about one-third of women who delivered a baby with congenital syphilis in 2016 were screened during their pregnancies.

The CDC, the American Academy of Pediatrics, and the American College of Obstetricians and Gynecologists all recommend repeat syphilis screening in women at high risk for syphilis at around 28 weeks of gestation and at time of delivery. Women at high risk include those living in higher-prevalence communities or geographic areas; those living with HIV infection; those with a history of incarceration or commercial sex work; and those exposed to a sexual partner with confirmed syphilis infection. Early penicillin treatment of infected pregnant women reduces the risk of congenital syphilis.

The USPSTF has also previously recommended screening nonpregnant adults and adolescents at increased risk for syphilis infection. Higher risk groups in nonpregnant adults are similar to those in pregnant women, but also include men who have sex with men (MSM), particularly men aged 20 to 29 years, whose prevalence of primary or secondary syphilis is nearly 3 times higher than that of the general U.S. male population. Finally, the USPSTF recommends intensive behavioral counseling for all sexually active adolescents and for adults at increased risk for sexually transmitted infections.