Rates of congenital syphilis have taken an ominous uptick over the past few years and are now at a 20-year high. The Centers for Disease Control and Prevention (CDC) reports that rates of primary and secondary syphilis in the general US population have increased 72.7% from 5.5 cases per 100,000 in 2013 to 9.5 per 100,000 in 2017 when a total of 30,644 cases were reported.1 The number of cases of congenital syphilis have increased simultaneously. After years of decline reaching a nadir in 2012, cases of congenital syphilis increased from 362 in 2013 to 918 in 2017 including 64 stillbirths and 13 infant deaths.1 During this time, the largest rate increases occurred in the Western United States (362.5%). Rates were highest among blacks (58.9 cases per 100,000 live births), followed by Native (indigenous) Americans (35.5 per 100,000), Hispanics (33.5 per 100,000), whites (9.7 per 100,000), and Asians/Pacific Islanders (4.3 per 100,000).
The consequences of congenital syphilis are so severe, and its prevention so straightforward, that this increase represents a public health tragedy. Thus, it is time to ensure that all pregnant women are adequately screened and expeditiously treated to eliminate this disease entirely. Fortunately, a few states are leading the way in curbing this epidemic and provide useful lessons for the rest of the nation.
Syphilis is caused by the spirochete Treponema pallidum. Primary syphilis is marked by presence of a chancre that heals in 3 to 6 weeks. Secondary syphilis, manifest by lymphadenopathy and/or a maculopapular rash on the palms, soles and mucous membrane, occurs in a quarter of cases6 weeks to 6 months after the chancre first appeared and lasts 2 to 5 weeks. Early latent syphilis occurs in the first full year, and late latent occurs thereafter. Tertiary syphilis is now rare with its classical gumma lesions and cardiac defects while neurosyphilis can begin with early disease and slowly progress to paresis if untreated.
Screening can employ either traditional or reverse sequence approaches.2 The former includes initial nontreponemal testing such as a quantitative Rapid Plasma Reagin (RPR) assay followed by confirmatory treponemal testing (e.g., Fluorescent treponemal antibody absorption test (FTA-ABS) or T. pallidum particle agglutination assay [TPPA]). Reverse sequence screening begins with an initial treponemal chemoluminescent or enzyme immunoassay with reflex testing of positive results (false positive results occur in 50% to 90% of cases) using a non-treponemal test such as quantitative RPR. If the RPR is positive it is diagnostic, but if negative, a final TPPA or FTA-ABS study is required to exclude the diagnosis.2
Treatment depends on the stage of the disease. For primary, secondary, and early latent disease a single dose of penicillin G benzathine (2.4 million units) is given intramuscularly. For late latent and tertiary disease, three weekly doses are required. Neurosyphilis requires inpatient parental therapy. While non-penicillin treatments (e.g., tetracycline) can be used in non-pregnant women, only penicillin G benzathine is appropriate in pregnancy. Thus, if pregnant patients are allergic, desensitization is needed. The biggest risk of treatment is the Jarisch-Herxheimer reaction occurring within 2 hours of treatment which can trigger preterm labor.
- Centers for Disease Control and Prevention. Sexually transmitted disease surveillance 2017. Atlanta: U.S. Department of Health and Human Services; 2018. Available at https://www.cdc.gov/std/stats17/2017-STD-Surveillance-Report_CDC-clearan... Accessed March 14, 2019.
- Lin JS, Eder ML, Bean SI. Screening for syphilis infection in pregnant women: updated evidence report and systematic review for the US Preventive Services Task Force. JAMA. 2018 Sep 4;320(9):918-925.
- Trivedi S, Williams C, Torrone E, Kidd S. National trends and reported risk factors among pregnant women with syphilis in the United States, 2012-2016. Obstet Gynecol. 2019 Jan;133(1):27-32.
- US Preventive Services Task Force, Curry SJ, Krist AH, et al. Screening for syphilis infection in pregnant women: US Preventive Services Task Force Reaffirmation Recommendation Statement. JAMA. 2018 Sep 4;320(9):911-917.
- Rubin R. Why are mothers still passing syphilis to their babies? Medical News & Perspectives. JAMA. 2019 Feb 6.
- Albright CM, Emerson JB, Werner EF, Hughes BL. Third-trimester prenatal syphilis screening: a cost-effectiveness analysis. Obstet Gynecol. 2015 Sep;126(3):479-85.