Vital Signs: Missed Opportunities for Preventing Congenital

Discussion

Lack of timely testing and adequate treatment during pregnancy contributed to 88% of congenital syphilis cases in 2022 and represent missed opportunities to prevent maternal syphilis-associated morbidity. Lack of timely testing and adequate treatment contributed to substantial proportions of cases in all geographic areas and in all racial and ethnic groups. Timely testing without evidence of late seroconversion occurred in 58% of cases; however, inadequate treatment occurred in 69% of these cases, and no treatment or nondocumented treatment in 19%. Treatment could be considered inadequate based on inappropriate selection of an antimicrobial agent, dosing, or spacing of doses, as well as an insufficient interval between initiation of treatment and delivery; ongoing analyses aim to describe specific sources of inadequate treatment to better guide public health action. Strategies that reduce loss to follow-up and decrease the time between testing and treatment could increase the likelihood of adequate treatment. This outcome has been achieved at some medical facilities and health organizations through implementation of rapid syphilis point-of-care testing (10), which the World Health Organization recommends during pregnancy in settings where a delay in diagnosis can lead to loss to follow-up (11). Innovations in treatment and close follow-up (e.g., field-delivered treatment and disease intervention specialists trained to prevent and control infectious diseases providing linkage to care) can help facilitate adequate treatment (12–14).

Recommended Treatment for Prevention of Congenital Syphilis

Benzathine penicillin G is the only recommended treatment for syphilis during pregnancy; this drug must be administered as an injection by a trained professional as either a single dose or as 3 doses spaced 7–9 days apart, depending on the stage of infection (6). The success rate of this treatment in preventing congenital syphilis has been reported to be as high as 98% (15). Although this analysis includes cases with clinical evidence of congenital syphilis despite adequate treatment, some of these cases might be explained by undetected reinfection late in pregnancy. Because the United States is currently facing a shortage of benzathine penicillin G, CDC has encouraged providers and health departments to prioritize benzathine penicillin G for the treatment of syphilis in pregnancy.^¶

Individual Screening Based on Risk Factors and Community Syphilis Rates

Historically, syphilis screening and interventions have targeted individual risk factors, but for many sexually active persons, their most significant risk factor is living in a community with high rates of syphilis (4,6). CDC guidelines recommend syphilis screening for sexually active persons in communities with high rates of syphilis (6); however, the threshold for a high rate is not defined. Currently, the Healthy People 2030 goal is to reduce the rate of primary and secondary syphilis cases among females aged 15–44 years to 4.6 per 100,000 population.** In counties with a rate that exceeds this goal, offering syphilis testing to sexually active females aged 15–44 years and their sex partners might help identify syphilis cases and prevent spread, support progress toward meeting the Healthy People 2030 goals, and reduce congenital syphilis. In 2021, 38% of U.S. counties, accounting for 72% of the U.S. population, had syphilis rates above the goal level^†† . Disparities in syphilis rates by race and ethnicity are not explained by differences in sexual behaviors, but rather reflect access to sexual health care, differences in sexual networks, and persistent and systemic racism in medical care (6,16). Screening based on geographic risk can decrease stigma and biases associated with screening based on individual risk factors. In counties already at or below the Healthy People 2030 goal level, clinicians should continue to assess individual risk factors (e.g., diagnosis of other sexually transmitted infections, a new partner, history of incarceration, transactional sex work, or being a male aged <29 years) to determine screening needs.^§§

More than 37% of infants with congenital syphilis were born to persons who had received no prenatal care. Among congenital syphilis cases, no or nontimely testing during pregnancy was the most frequently missed opportunity identified among birth parents without documented prenatal care. Among those with a timely test obtained during pregnancy, 20.4% had no prenatal care documented, suggesting that testing occurred outside prenatal care. In addition to improving access to prenatal care, approaches to providing care outside of clinical settings (e.g., use of rapid tests, field-delivered treatment, active case follow-up, and linkage to care by disease intervention specialists) are needed to ensure appropriate and timely screening and treatment. Any encounter with medical or public health professionals during pregnancy is an opportunity to identify and treat syphilis, thereby preventing congenital syphilis as well as maternal morbidity. Screening for syphilis at encounters outside traditional prenatal care (e.g., emergency department, jail intake, syringe services program, and maternal and child health programs) might help identify and treat persons with syphilis who might not otherwise receive adequate prenatal care (13,14,17–19). In addition, the identification of syphilis during pregnancy should be seen as a high priority for rapid follow-up, with a systematic approach to defining who will be responsible for ensuring timely treatment.

Limitations

The findings in this report are subject to at least three limitations. First, national congenital syphilis case data contain limited information about social determinants of health. The underlying individual and structural barriers (e.g., systemic inequities and limited health care access) leading to the missed opportunities described in this report are beyond the scope of this analysis. Second, jurisdictional differences in reporting completeness and accuracy for congenital syphilis cases likely exist, including differing legal requirements for screening. Differential reporting might have resulted in misclassification of the missed opportunities, amplifying regional differences. Finally, national case data provide limited information on the breadth of syphilis testing during pregnancy (e.g., prepregnancy testing and the titers of syphilis tests measured during pregnancy), which might lead to misclassification both in the context of a history of adequately treated syphilis, as well as seroconversion late in pregnancy. Testing and treatment that occurred but are not documented cannot be assessed.

Implications for Public Health Practice

Congenital syphilis rates are rapidly increasing in the United States and are at the highest level in at least 30 years (4). Barriers to congenital syphilis prevention are multifactorial, including those at the patient level, such as substance use and insurance status, and those at the system level, such as structural inequities, limited access to health care, and medication shortages (5,8,16,17,20). Addressing patient and system-level barriers to accessing testing, treatment, and care could help prevent congenital syphilis. Improvements in timely testing and appropriate treatment of syphilis through tailored strategies at local and national levels will help control the congenital syphilis epidemic in the United States.