Trends in syphilis testing and infections in New York: insights into testing volume, positivity, and demographics

Syphilis has re-emerged as a major public health concern with substantial geographic and demographic heterogeneity. Laboratory data provides an objective view of disease burden that complements traditional surveillance.

We conducted a retrospective analysis of syphilis serologic testing performed from 2020 to 2024 at two academic medical centers representing East and West Manhattan within a large healthcare system. We evaluated trends in testing volume, proportion of positive tests, patient demographics among all tested individuals, and newly identified positive patients including those with high rapid plasma reagin titers.

A total of 524,147 syphilis tests were performed, with steadily increasing volumes at both sites. Overall proportion of positive tests remained stable from 2020 to 2024; however, the West campus consistently demonstrated nearly two-fold higher proportion of positives than the East campus (4.0-4.6% vs. 2.1-2.6%, p<0.001). Among newly tested patients, positivity was stable over time but significantly higher at the West campus, where newly positive patients were younger and more likely to be female (19-23% vs. 11-18%, p<0.001). Median age of newly positive patients declined at both sites between 2021 and 2024 (East: 47 to 40 years; West: 43 to 35 years; p<0.001). The proportion of high-titer infections did not differ between sites and declined in 2024 compared with 2023.

Laboratory-based surveillance revealed overall stable syphilis positivity but persistent geographic and demographic disparities within an urban healthcare system, and support geographically targeted, equity-focused syphilis screening and prevention, particularly for younger populations and women of reproductive age.