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

The Mortality of Congenital Syphilis

OBJECTIVES

To document the case-fatality rate (CFR) of congenital syphilis diagnosed by molecular tools and rabbit infectivity testing (RIT) of clinical specimens in addition to standard evaluation and to compare that with the CFR using the Centers for Disease Control and Prevention (CDC) surveillance case definition.

STUDY DESIGN

Prospective, single site, cohort study of all cases of syphilis among mothers and their infants from 1984 to 2002. The diagnosis of congenital syphilis was determined using IgM immunoblotting, polymerase chain reaction, and RIT of fetal or infant specimens in addition to clinical, laboratory, and radiographic criteria. Data were retrospectively reviewed to ascertain fetal and neonatal mortality.

RESULTS

During the 18-year study, there were 191 cases of congenital syphilis confirmed by abnormalities on clinical, laboratory, or radiographic evaluation and/or positive serum IgM immunoblot, blood polymerase chain reaction, or blood/cerebrospinal fluid RIT. Of the 191 cases, 59 died for a CFR of 31%. Of the 59 deaths, 53 (90%) were stillborn and 6 (10%) died in the neonatal period. The majority (74%, 39/53) of stillbirths occurred in the third trimester. The CDC surveillance case definition correctly identified all infants with congenital syphilis, but the CDC CFR was 10% which underestimated the CFR by more than 300%.

CONCLUSIONS

Our findings corroborate the high sensitivity of the CDC surveillance definition for congenital syphilis but highlight its poor estimation of its associated mortality. The CFR among infected progeny of pregnant women with syphilis was 31%, due mostly to demise in the third trimester and as such highlights the need for detection and appropriate treatment of syphilis during pregnancy.

Congenital Syphilis-An Illustrative Review

Congenital syphilis is caused by the spirochete, Treponema pallidum, which can be transmitted from an infected mother to her fetus during pregnancy or by contact with a maternal lesion at the time of delivery. The incidence of congenital syphilis is rapidly increasing all over world with 700,000 to 1.5 million cases reported annually between 2016 and 2023. Despite the widespread availability of Penicillin, 2677 cases were reported in 2021 in the US. Clinical manifestations at birth can vary widely ranging from asymptomatic infection to stillbirth or neonatal death. Low birth weight, rash, hepatosplenomegaly, osteolytic bone lesions, pseudoparalysis, central nervous system infection, and long-term disabilities have been reported in newborns with congenital syphilis. Prevention of congenital syphilis is multifaceted and involves routine antenatal screening, timely treatment of perinatal syphilis with penicillin, partner tracing and treatment, and health education programs emphasizing safe sex practices and strategies to curb illicit drug use. Neonatal management includes risk stratification based on maternal syphilis history, evaluation (nontreponemal testing, complete blood counts, cerebrospinal fluid, and long-bone analysis), treatment with penicillin, and followup treponemal testing. Public health measures that enhance early detection during pregnancy and treatment with penicillin, especially in high-risk mothers, are urgently needed to prevent future cases of congenital syphilis.

Examining associations in congenital syphilis infection and socioeconomic factors between California's small-to-medium and large metro counties

OBJECTIVE

To investigate differences in congenital syphilis (CS) infection between California's small-to-medium and large metropolitan counties and the socioeconomic mechanisms behind these differences.

STUDY DESIGN

County-level data from 2019 and 2020 on CS infection and other socioeconomic covariates were obtained from the California Department of Public Health and the United States Census Bureau. Counties were stratified into small-to-medium or large metropolitan counties by the National Center for Health Statistics Urban-Rural Classification Scheme and analyzed using simple and multiple Poisson regression models.

RESULTS

California's small-to-medium metropolitan counties reported significantly higher rates of CS incidence, female poverty, and uninsured females, and significantly lower rates of English-language speaking ability and female education level compared to large metropolitan counties. CS infection was significantly associated with female poverty and education level.

CONCLUSION

Rates of CS infection in the California counties are more dependent on socioeconomic indicators than county classification itself.

New trends in congenital syphilis: epidemiology, testing in pregnancy, and management

PURPOSE OF REVIEW

In light of alarming increases in the incidence of congenital syphilis in many middle and higher income countries across the globe, this review summarizes recent changes in the epidemiology of syphilis, highlights recommended changes to testing in pregnancy and provides an update for the management of syphilis infection in pregnancy (SIP) and of the infant born to a mother with SIP.

RECENT FINDINGS

The re-emergence of congenital syphilis is a result of increasing infectious syphilis in women of childbearing age, which is in turn a result of increasing syphilis in the general population particularly in Indigenous and marginalized populations. Potential reasons for the increase include changing sexual practices and increased travel and migration, as well as factors that limit healthcare access, particularly access to antenatal care and limited awareness and education amongst mothers and maternity services. A single antenatal test for syphilis is insufficient; more frequent testing in pregnancy is necessary even for women deemed to be low risk. The management of SIP and of the newborn is complex and guidelines should be readily available with clear recommendations.

SUMMARY

Congenital syphilis is preventable. The current crisis calls for a global and national multipronged, co-ordinated approach involving public health and hospital systems which includes education of individuals and healthcare workers, availability of updated guidelines for prevention and treatment, prioritization of antenatal testing, assurance of accessible and prompt treatment and appropriate assessment and follow-up of infants.

Understanding perinatal patient's health preferences and patient-provider relationships to prevent congenital syphilis in California and Louisiana

Background

Congenital syphilis (CS) has reemerged as a global maternal and child health crisis. Kern County, California and East Baton Rouge Parish, Louisiana are among the highest CS morbidity regions in the United States. We previously reported on social-ecological and structural barriers to prenatal care and maternal syphilis testing and treatment in these two regions. The aim of this study was to examine perinatal patient’s health preferences and perceptions of patient-provider relationships in the prenatal care clinic setting.

Methods

Between May 2018 and January 2019 we conducted 20 in-depth qualitative interviews with prenatal providers and 8 focus group discussions with pregnant and postpartum individuals in Kern County and East Baton Rouge Parish. We applied an adapted health services framework to analyze participants’ understanding of health disparities and vulnerable populations; perinatal patient’s health and prenatal care preferences; and participants’ perspectives of clinical encounters in the context of prenatal care and maternal syphilis testing and treatment.

Results

Site-specific determinants of syphilis infection emerged but participants from both locations felt CS prevention efforts should be prioritized among youth, racial/ethnic minority populations, people experiencing socioeconomic limitations and people with other commonly occurring health conditions. Although perinatal patients expressed clear health preferences, they reported inconsistent receipt of respectful, patient-centered care. Inconsistencies were connected with limited ethnic and cultural competence among providers, and implicit, negative attitudes toward patients using substances, experiencing homelessness, or engaging in sex work. Providers clearly aimed to offer high quality prenatal care. However, some clinic and health systems level factors were thought to reduce positive and communicative patient-provider relationships, contributing to gaps in use of prenatal care and syphilis testing and treatment.

Conclusions

Our findings suggest that interventions tailored to address setting-specific determinants (including clinic and health system factors) of disparities in CS risk could improve pregnant people’s access to prenatal care and ensure they and their sex partners receive timely syphilis screening and treatment. We recommend all prenatal care providers receive training on how to identify and mitigate implicit biases and provide competent and compassionate patient-centered care.

Amoxicillin as an Option in Congenital Syphilis Management: A Case Report

BACKGROUND: Congenital syphilis (CS) is the second leading cause of preventable stillbirth globally. This case report shows that CS baby can be managed by amoxicillin with good results. CASE PRESENTATION: A term female baby was born through section cesarean on suspicion of syphilis of a 29-year-old mother, G4P3A0, 39 weeks gestation with normal APGAR score, and birth weight was 2330 g, birth length was 46 cm, and head circumference 32 cm. There are no abnormalities on physical examination. The baby is active and clinically sound. In history taking, the mother was diagnosed with syphilis in the first trimester of pregnancy but did not want to be treated. After birth, maternal serology showed that Treponema pallidum is reactive. Maternal VDRL was reactive at 1:1, while TPHA was reactive at 1:2560. Baby laboratory results showed Hb 18.4 g/dL, leukocytes 33,480/μL, platelets 278,000/μL, and hematocrit 54.7%. A peripheral blood smear showed neutrophilia with hypersegmentation and monocytosis due to suspected chronic inflammation. Baby VDRL was reactive at 1:16, while TPHA was reactive at 1:1280. The diagnosis was congenital syphilis with low birth weight and small for gestational age. After one month of treatment with oral amoxicillin, baby VDRL was reactive at 1:2, while TPHA was reactive at 1:320. At 1½ months, the baby’s hemoglobin is 10.1 g/dL. X-rays for chest, abdomen, and skeletal were within normal limits. The baby was given oral amoxicillin 50 mg/kg/day for a total of 3 months. When the baby was 4 months old, her growth and development were good with the VDRL reactive 1:1 and the TPHA reactive 1:160. CONCLUSION: In the unavailability of benzathine penicillin, amoxicillin may be considered an option in CS management.

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

Background

Congenital syphilis is preventable through timely access to prenatal care, syphilis screening and treatment of pregnant women diagnosed as infected. In 2018, California had the second highest number of congenital syphilis cases in the United States (U.S.), a nearly twofold increase in cases since 2014. This study assessed gaps in preventing congenital syphilis in the high morbidity region of Kern County, California.

Methods

Between May 2018 and January 2019, we conducted five focus group discussions with pregnant/postpartum women and ten semi-structured interviews with prenatal care providers in Kern County. Focus group and interview data were recorded, transcribed, and analyzed to identify emergent themes pertaining to facilitators and barriers at each step (prenatal care, syphilis screening and treatment) in the congenital syphilis prevention cascade.

Results

Gaps in congenital syphilis prevention discussed in focus group discussions with pregnant/postpartum women were related to limited prenatal care access, social-, economic-, and cultural-barriers, and substance use and co-occurring intimate partner/domestic violence. The gaps identified from interviews with prenatal care providers included social economic vulnerabilities of pregnant women and stigma and shame around the vulnerabilities, distrust in medical system, prenatal substance use, limited prenatal substance use disorder treatment facilities, and inadequate provider training on context-specific congenital syphilis management strategies. Gaps in partner notification, screening and treatment for syphilis were brought up by pregnant/postpartum women and prenatal care providers.

Conclusions

Congenital syphilis continues to increase in Kern County and throughout the U.S. In high syphilis morbidity areas, comprehensive and tailored public health approaches addressing setting-specific gaps in prenatal screening and treatment are needed.

Syphilis in Neonates and Infants

Syphilis in neonates and infants remains a significant public health problem because it is a major cause of fetal and neonatal morbidity and mortality globally. Despite decades of experience with syphilis in adults and infants, maternal and congenital syphilis are increasing substantially in the United States. The vertical transmission, clinical manifestations, diagnosis, evaluation, treatment, and follow-up are reviewed to guide the health care professional in understanding the optimal management of this preventable disease.