Evolving Trends in Racial and Ethnic Disparities in Syphilis Prevalence Among People Who are Pregnant in The United States from 2016 To 2023
Author(s)
Yizhi Liang, MBBS, MS1, Nicolas Menzies, PhD, MPH2, Minttu Rönn, PhD, MPH2;
1University of Southern California, Department of Pharmaceutical and Health Economics, School of Pharmacy, Los Angeles, CA, USA, 2Harvard T.H. Chan School of Public Health, Department of Global Health and Population, Boston, MA, USA
1University of Southern California, Department of Pharmaceutical and Health Economics, School of Pharmacy, Los Angeles, CA, USA, 2Harvard T.H. Chan School of Public Health, Department of Global Health and Population, Boston, MA, USA
Presentation Documents
OBJECTIVES: The number of syphilis diagnoses in the United States has risen progressively. The incidence of congenital syphilis (vertical transmission during pregnancy) has increased in parallel. Syphilis is a curable infection, and early treatment can prevent vertical transmission. Clinical guidelines recommend at least one syphilis screening during pregnancy. Notable racial/ethnic disparities have been reported for both outcomes. We estimated syphilis prevalence among pregnant women by race/ethnicity from 2016 to 2023, using nationally representative data and accounting for test performance and differences in testing coverage during pregnancy.
METHODS: We analyzed data on syphilis infection from U.S. birth certificates using a Bayesian mathematical model, adjusting for test sensitivity, specificity, and screening coverage. Uncertainty exists on screening coverage achieved among people who are pregnant in the US. We calibrated the model under two scenarios: (1) assuming screening coverage is as estimated in Medicaid claims data and (2) assuming higher screening coverage than observed in Medicaid claims. We compared the estimates to stillbirths attributable to syphilis reported through routine surveillance. We examined racial and ethnic disparities using the index of disparity.
RESULTS: In Scenario 1, syphilis prevalence among people who are pregnant with live births increased from 101.1 (95% uncertainty interval [UI]: 87.5, 120.5) per 100,000 live births in 2016 to 533.4 (95% UI: 496.6, 581.0) per 100,000 live births in 2023. In Scenario 2, prevalence increased from 73.9 (95% UI: 51.2, 130.0) per 100,000 live births to 378.1 (95% UI: 295.5, 592.0) per 100,000 live births over the same period. With rising prevalence, relative racial and ethnic disparities narrowed over time. Prevalence was estimated to be higher among women with stillbirths compared to women with live births.
CONCLUSIONS: In the United States, improved estimates of screening coverage are needed to understand the gaps in congenital syphilis prevention and to inform estimates of syphilis prevalence among pregnant persons.
METHODS: We analyzed data on syphilis infection from U.S. birth certificates using a Bayesian mathematical model, adjusting for test sensitivity, specificity, and screening coverage. Uncertainty exists on screening coverage achieved among people who are pregnant in the US. We calibrated the model under two scenarios: (1) assuming screening coverage is as estimated in Medicaid claims data and (2) assuming higher screening coverage than observed in Medicaid claims. We compared the estimates to stillbirths attributable to syphilis reported through routine surveillance. We examined racial and ethnic disparities using the index of disparity.
RESULTS: In Scenario 1, syphilis prevalence among people who are pregnant with live births increased from 101.1 (95% uncertainty interval [UI]: 87.5, 120.5) per 100,000 live births in 2016 to 533.4 (95% UI: 496.6, 581.0) per 100,000 live births in 2023. In Scenario 2, prevalence increased from 73.9 (95% UI: 51.2, 130.0) per 100,000 live births to 378.1 (95% UI: 295.5, 592.0) per 100,000 live births over the same period. With rising prevalence, relative racial and ethnic disparities narrowed over time. Prevalence was estimated to be higher among women with stillbirths compared to women with live births.
CONCLUSIONS: In the United States, improved estimates of screening coverage are needed to understand the gaps in congenital syphilis prevention and to inform estimates of syphilis prevalence among pregnant persons.
Conference/Value in Health Info
2025-05, ISPOR 2025, Montréal, Quebec, CA
Value in Health, Volume 28, Issue S1
Code
PT30
Topic
Epidemiology & Public Health
Disease
SDC: Infectious Disease (non-vaccine)