Using Surveillance Data to Respond to an Outbreak of Congenital Syphilis in Arizona Through Third-Trimester Screening Policies, 2017-2018.

Introduction: The number of congenital syphilis (CS) cases in Arizona quadrupled from an average of 14 cases annually before 2017 to 61 cases in 2018, and a statewide outbreak was declared. The Arizona Department of Health Services (ADHS) analyzed statewide surveillance data to identify missed opportunities for prevention and collaborated with the Arizona Health Care Cost Containment System (AHCCCS) to inform response activities.

Methods: ADHS developed a metric to identify missed opportunities for CS prevention during pregnancy by using medical records, vital records, and case investigation notes for all mothers of infants born with CS from January 1, 2017, through June 30, 2018. AHCCCS conducted a cost-effectiveness analysis to calculate the effect of increasing perinatal syphilis screening.

Results: Arizona had 57 cases of CS during the study period, of which 17 (29.8%) could have been prevented through third-trimester screening for women who were in prenatal care but screened late (n = 9), were infected after their first prenatal visit screen (n = 7), or were reinfected after an initial reactive syphilis test and appropriate treatment and not rescreened (n = 1). The estimated net cost of combining the additional primary (screening) and secondary (treatment) costs of a third-trimester screen for all pregnant AHCCCS members and the estimated total per-year savings of all newborn hospitalizations was $527.

Practice Implications: Third-trimester syphilis screening could prevent CS in regions where syphilis transmission is high. Partnering with health insurance agencies to evaluate the cost effectiveness of screening recommendations may improve the accuracy of the estimate of the potential cost savings by using insurance agency-specific data for the population at risk for CS.