From the Research
The CDC recommends routine syphilis screening for pregnant women, sexually active men who have sex with men (MSM), people with HIV, and individuals with risk factors such as multiple sex partners or living in high-prevalence areas. Testing involves a two-step approach: initial screening with a nontreponemal test (RPR or VDRL) followed by confirmation with a treponemal test (TP-PA, FTA-ABS, or treponemal immunoassays) if positive, as supported by the most recent study 1. Some labs use the reverse sequence algorithm, starting with a treponemal test and confirming positive results with a nontreponemal test.
Key Recommendations
- For pregnant women, screening should occur at the first prenatal visit, with additional testing at 28 weeks and delivery for those at high risk, as recommended by the CDC and supported by studies such as 2 and 1.
- MSM should be screened at least annually, with more frequent testing (every 3-6 months) for those with multiple partners.
- People diagnosed with syphilis should be tested for HIV and other STIs.
- Follow-up testing with nontreponemal tests is essential to monitor treatment response, with titers expected to decline fourfold within 6-12 months, as noted in 3.
Rationale
This two-test approach is necessary because treponemal antibodies typically remain positive for life, while nontreponemal test titers correlate with disease activity and can be used to monitor treatment effectiveness. The CDC guidelines are supported by various studies, including those that highlight the importance of prenatal syphilis screening in preventing congenital syphilis and its associated morbidity and mortality 4, 5, 3.
Additional Considerations
- The screening rates and recommendations may vary by state and region, with some states having more stringent requirements for prenatal syphilis screening, as noted in 5.
- The use of point-of-care syphilis testing may be a useful strategy to improve screening rates and reduce perinatal mortality, especially in resource-poor settings, as suggested by 4.