Congenital Syphilis: The Need for a Simpler and More Precise Diagnosis

Congenital syphilis is resurging in the United States, with incidence at its highest level in decades. Despite significant advances in infectious disease diagnostics, clinicians still lack a sensitive method to exclude congenital syphilis in exposed neonates, especially those who are asymptomatic. Current diagnostic strategies rely heavily on maternal treatment history, infant physical examination, and comparison of maternal and infant nontreponemal titers-components that are difficult to interpret, have limited sensitivity, and may not meaningfully alter management. As a result, many infants are hospitalized and treated not because infection is confirmed, but because it cannot be reliably ruled out.

We conducted a narrative review of historical and contemporary studies evaluating diagnostic approaches for congenital syphilis.

This review highlights 2 core diagnostic challenges in congenital syphilis: first, the current evaluation process is complex, difficult to interpret, and insufficiently sensitive to exclude infection, leading to both overtreatment and missed cases. Second, despite promising evidence from research settings, promising diagnostic tools such as immunoglobulin M-based assays and molecular tests that directly detect Treponema pallidum remain largely unused in routine US practice. Across historical and contemporary studies, those modalities demonstrated complementary strengths and may offer a simpler and more precise diagnostic approach that could reliably rule out infection in exposed but uninfected infants, an urgent and unmet need in current clinical care. Although those tools are used in parts of Europe, Asia, and other regions, they lack standardized protocols, regulatory clearance, and clinical integration in the United States.

Broader implementation of these diagnostic tools could streamline evaluation, improve diagnostic accuracy, reduce unnecessary hospitalization and antibiotic use, and ensure timely treatment for infected neonates. Future efforts should prioritize clinical validation studies, standardized protocols, and long-term serologic follow-up to support evidence-based care for infants at risk of congenital syphilis.