A Narrative Review of the Epidemiology of Congenital Syphilis in the United States From 1980 to 2019

Abstract

Objectives Congenital syphilis (CS) is the result of antepartum transmission from mother to fetus of the spirochete Treponema pallidum. Although preventable through timely screening and treatment, the incidence of CS in the United States is increasing. This review describes the epidemiological trends in CS in the United States from 1980 to 2019 and characteristics of mothers of infants with CS. Methods We performed a narrative review of epidemiological studies of CS following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for reporting of observational studies in epidemiology. Quality and bias of included studies were assessed using the Newcastle-Ottawa Scale. Studies that described the demographics and characteristics of pregnant women with syphilis or who delivered an infant with CS in the United States were identified from PubMed and Embase. Results We identified a total of 2771 studies, of which 309 were selected for further review and 27 were included in the final analysis. Substance use during pregnancy was a risk factor for CS in 16 studies. Maternal cocaine use was described in 11 of the 16 studies, 10 of which were published between the years 1980 and 1999. No prenatal care was a risk factor for CS in 17 studies. Evidence of inadequate syphilis testing (i.e., no maternal screen, first screen after the first trimester, or no repeat screen in third trimester) or treatment (i.e., no treatment, treatment <30 days before delivery, or nonpenicillin treatment) was significantly associated with CS in 13 studies. Finally, higher rates of CS were reported among African American women in 11 studies. Conclusions Infection with and antepartum transmission of syphilis disproportionately affect certain subgroups of women. Women who report substance use during pregnancy are more likely to give birth to an infant with CS. No prenatal care and evidence of inadequate syphilis testing and treatment during pregnancy are also significantly associated with giving birth to an infant with CS. Finally, cases of CS disproportionately affect African American women. Addressing the CS epidemic will require identification and targeted allocation of resources to communities at elevated risk for syphilis, removal of barriers to prenatal care, and ensuring timely treatment and adequate partner notification of identified cases.

A qualitative assessment of structural barriers to prenatal care and congenital syphilis prevention in Kern County, California

“…The rise in congenital syphilis incidence is part of a larger trend of increased syphilis infections [ 4 ]. The Centers for Disease Control and Prevention (CDC) recommends screening of all pregnant persons for syphilis at the first prenatal care visit, with additional screening during the third trimester and at delivery in areas or populations where the risk of syphilis is high [ 5 ].…”

“…Congenital syphilis cases are associated with late initiation and lack of prenatal care, and case rates are disproportionately high in the most socially vulnerable communities; social vulnerability and deprivation in mothers is often associated with an increase risk of inadequate prenatal care [ 6 ]. Numerous structural factors are related to lack of timely and adequate prenatal care, including lack of insurance, cost of co- pays, lack of transportation or child care, unawareness of the pregnancy, and mental health and substance use issues [ 4 ]. Despite an increasing recognition of the structural determinants of health–those determinants driven by political, social and economic forces which produce and maintain poor health outcomes–most research into congenital syphilis has focused on the individual psychosocial and behavioral factors that contribute to maternal vulnerability for syphilis.…”

Gaps in the congenital syphilis prevention cascade: qualitative findings from Kern County, California

“…Rates of primary and secondary syphilis among heterosexual women of reproductive age in the U.S. doubled during approximately the same time period (i.e., 2014–2018), and a directly correlated increase in new CS cases was concurrently observed [ 3 ]. Extensive research focused specifically on health outcomes during pregnancy in the U.S. found substance use was associated with mother to child transmission of syphilis [ 19 , 22 ].…”

Understanding Perinatal Women’s Health Preferences and Patient-Provider Relationships to Prevent Congenital Syphilis in California and Louisiana

“…Participants agreed with the CDC's widely accepted de nition of pregnant women being at highest risk for syphilis if they had a history of past (syphilis) infection, incarceration, drug use, or multiple or concurrent sex partners [24]. Research from several other studies in the U.S. [27], including California [28] also identi ed some or all of these same factors as determinants of risk for syphilis in pregnant women. In our study, we learned that the de nition of vulnerable population, as related to CS risk in Kern County and Baton Rouge, was incomplete without also including racial/ethnic minority populations, people experiencing transient economic and/or social resource limitations, people with a history of other health conditions, and youth.…”