Purpose: Syphilis is an important public health problem in sub-Saharan Africa with prevalence ranging from 3%-17%. Pregnant women are a critical target population for screening because the consequences of infection extend to their unborn children. We evaluate the cost-effectiveness of universal prenatal syphilis screening with rapid tests developed for use in the field and capable of providing same-day results.

Methods: We developed a computer-based model that simulates the acquisition and subsequent natural history of syphilis in pregnant sub-Saharan African women. An initial cohort of 15 year old non-pregnant adolescents are followed throughout their lifetime according to transition probabilities extrapolated from the literature. Health states are stratified by pregnancy status (first, second and third trimester) and stage of syphilis (primary, secondary, early latent and late latent syphilis). Direct medical, nonmedical and time costs were expressed in 2002 International Dollars ($I). Model outcomes include adverse pregnancy outcomes (miscarriage, low birth weight, congenital syphilis, stillborn, and neonatal death), maternal life expectancy, and lifetime costs. Strategies include: (1) No screening, (2) Standard screening using Rapid Plasma Reagin (RPR) test followed by Treponema pallidum Hemagglutination Assay (TPHA) confirmatory test, (3) Rapid testing with RPR (RT-RPR); (4) Rapid testing with enzyme immunoassay (EIA) (RT-EIA).

Results: In the absence of screening, for a high-risk cohort of 1000 women with 6 pregnancies each, there were 256 cases of congenital syphilis, 583 low birth weight infants and 170 stillbirths or neonatal deaths. In comparison, all screening strategies were more effective and less costly. The most effective and least costly strategy was RT-EIA, which averted 178 cases of congenital syphilis, 43 low birth weight infants and 37 perinatal deaths, increased maternal LE by 0.06 years, and saved $575, compared with no screening. Over a wide range of sensitivity analyses rapid testing dominated standard screening, although the choice between RT-EIA and RT-RPR was sensitive to test kit, labor and supply costs, and test sensitivity. RT-RPR became the optimal strategy only when the cost of RT-EIA more than doubled or its sensitivity fell below 88%.

Conclusions: Universal prenatal syphilis screening using rapid point of care tests will improve both maternal and infant outcomes and is cost-effective.