Congenital Syphilis: A Persisting Sentinel Public Health Event

CONGENITAL SYPHILIS (CS) IS A sentinel public health event because of its devastating consequences and persistence throughout the United States.1 Within 4 years of becoming infected with syphilis, a pregnant woman has a 70% probability of transmitting the infection to her fetus. Untreated syphilis among pregnant women may result in spontaneous abortions, stillbirths, and perinatal death. Infected liveborn infants may develop a highly infectious nasal discharge, experience deafness, and have abnormalities of the skin, liver, teeth, bone, and nervous system. The prevention of CS is based on screening pregnant women for syphilis and providing to those infected timely treatment with penicillin, which is highly effective, safe, and the only recommended medication for pregnant women with syphilis.2 Guidelines from the Centers for Disease Control and Prevention (CDC) and other organizations recommend that all pregnant women be screened for syphilis.2–4 In areas or populations at high risk for syphilis, pregnant women should be screened 3 times. CDC guidelines, for example, recommend screening with a nontreponemal test at the first prenatal care (PNC) visit, at 28 weeks of gestation, and at delivery. Whereas the purpose of the test at delivery is primarily to detect CS cases (in addition to treating infected women), the purpose of the first 2 tests is prevention of CS. The management of infected women who are treated includes follow-up nontreponemal titers to assess the response to treatment and to document that reinfection has not occurred. In persons for whom PNC is not optimal, rapid screening and treatment should be conducted at the time pregnancy is confirmed and based on a reactive rapid plasma reagin-card test.2 Screening pregnant women for syphilis has been the foundation of CS prevention; however, the lack of published studies that fully document screening practices and associated outcomes (testing and clinical) is disappointing. Some studies have documented reported screening practices from provider surveys,5–9 but these data are limited because the actual practices are unknown. Other studies have used data from patient-related records but are limited by not clearly specifying the number of tests performed (i.e., 0, 1, 2, and 3).10–15 The relationship between syphilis screening and the adequacy of PNC and prenatal clinic type (public vs. private) has been minimally addressed. In this issue of Sexually Transmitted Diseases, Trepka et al describe a study that uses patient records to document the proportion of pregnant women who received at least one screening test during PNC (83%), 2 tests during PNC (11%), and 3 tests—2 during PNC and one at delivery (9%). These results, from an area of high syphilis prevalence, suggest that an unacceptably low proportion of pregnant women were screened according to guidelines. In contrast to the other studies,5–15 the authors use regression analysis to account for PNC adequacy (assessed by 2 different measures) and prenatal clinic type. The results show that attending a private prenatal clinic is associated with not being screened at all during PNC and also not being screened twice during PNC despite otherwise adequate PNC. Additionally, the authors document syphilis outcomes for the mothers and infants and confirm that all cases were reported to the health department. Four important issues emerge from this study. First, the authors confirm, in more detail than previously reported, that documented screening practices are not consistent with guidelines, which have been in place for nearly 20 years.16 Reasons given in this study include lack of provider awareness of high syphilis rates, state laws, and national guidelines. Although these reasons are likely to contribute to this inconsistency, providers who are aware but not complying is also possible. For example, the inability to bill or lack of insurance coverage for tests was a barrier to screening in one study.7 A better understanding of healthcare systems and the testing practices and decision-making of providers would help inform strategies being considered to ensure awareness and compliance with state laws and national guidelines. Second, CS is traditionally thought of as occurring primarily in populations who attend public sector health care, but an increasing proportion of health care is being provided by managed care organizations, which do not consider bacterial sexually transmitted diseases a priority.17 Furthermore, female cases of primary and secondary syphilis reported to the CDC from private physicians and health maintenance organizations have increased from 17% to 21% during 2000–2004. With data from the public and private sectors, Trepka et al conclude that private PNC is associated with not receiving recommended screening tests. This is an important point that warrants further scrutiny of their results. The unadjusted and adjusted odds ratios for both private PNC clinic type and private payment clearly show an association with women not being screened twice during PNC. The findings are less clear, however, when considering women not being screened at all, because the odds ratios do not show the same association. The data suggest that public and private providers are equally likely to screen once but that private sector providers are less likely than those in the public sector to screen twice. As the authors state, private providers may not have encountered syphilis cases in their practice and may be assuming that their patients are not at risk for syphilis.17 Given that syphilis rates have been at historic lows among heterosexuals, private providers could be thinking that the probability of infection is now lower in general and that the probability of a positive test in the third trimester after a negative syphilis test early in pregnancy may be similarly low. Indeed, results of one study of medical claims from a commercially insured population showed that prenatal screening (at least once) was significantly higher in areas of high syphilis morbidity.10 Nevertheless, more information is needed about private providers' perceptions of infection probabilities and which patients are at risk for syphilis. Third, inadequate or no PNC has generally been associated with a failure to be tested during pregnancy and thus with CS, yet Trepka et al present findings that are somewhat counterintuitive, i.e., no such association, despite assessing PNC by 2 different established PNC indices. The authors correctly state that these indices are limited because they reflect the use of care and not quality; however, the lack of association may not be as clear as the authors state. Women who received “adequate plus” PNC were less likely to have been screened twice, whereas women whose care was adequate, “intermediate,” or inadequate were more likely to have been screened at least twice. Such findings are not easily explained but may be related to interaction between variables (e.g., PNC index and prenatal clinic type). More specifically, private care providers are less likely to screen more than once and may be more likely to have patients with enough visits to qualify as receiving “adequate plus” PNC. Public health professionals are increasingly being required to use evidence-based policies, be more accountable for their actions, and evaluate their programs and interventions. Consequently, the development and careful use and analysis of PNC quality measures are needed. Fourth, case report data provide the foundation for trends and other statistics, which are important to the design of effective prevention interventions, but underreporting commonly occurs.8 Providers should understand their critical role in case reporting, report all confirmed and suspected CS cases to the appropriate health department, and request assistance from public health staff as needed (e.g., with partner notification). To help overcome obstacles and delays in reporting, public health professionals should engage providers and hospitals to ensure that all possible and confirmed CS cases are identified and reported. Additionally, sexually transmitted disease reports with syphilis statistics by locale can be provided to clinicians, thus demonstrating to them the relevance of evidence-based approaches to managing and preventing disease at the population and individual levels. Even when cases are reported, complete reporting of key variables on the surveillance report form can be problematic.14 For example, persons responsible for abstracting the required information may not have been able to access the needed records, and when available, hospital records may be incomplete (e.g., prenatal tests and results may not have been forwarded, omission of information resulting from confidentiality concerns). To help ensure that reported CS cases are truly cases and that case reports have the most accurate information possible, professionals responsible for case reporting should ensure accurate and complete information on the surveillance case report forms. As this article illustrates, research is needed that compares public and private sectors with regard to CS prevention activities. Evaluations could identify problems and solutions associated with underreporting and incomplete report forms. More precise measures of the number, timing, and outcomes of tests would help determine the usefulness of the recommended tests, particularly the second one (e.g., probability of a second test being positive after an initial negative one). A large-scale study could determine the prevalence of syphilis among pregnant women who do and do not obtain PNC and include maternal and infant outcomes. We commend Trepka et al for advancing the understanding of PNC screening practices and outcomes. Given the importance and urgency of the national Syphilis Elimination Effort,1 more resources and research should be directed toward CS prevention. With clear syphilis prevention guidelines and inexpensive, effective treatment, CS should not occur. Now is the time for enhanced, coordinated efforts by providers and public health professionals to prevent CS. Sentinel public health events serve as a warning signal that the quality of prevention and medical care may need to be improved.18 In 2004, 343 CS cases were reported to the CDC—343 warning signals that suggest syphilis prevention and prenatal care need improving.