STI testing and diagnosis rates among patients with Mpox in 2 populous US cities, 2022

Mpox is recognized as a sexually transmitted infection, and the 2022 epidemic and 2024 resurgence of mpox cases through sexual transmission highlighted the need for sexually transmitted infection (STI) testing. Our objective was to observe rates of STI testing and STI diagnoses in patients with confirmed mpox in Houston, Texas and New York City, New York (NY).

This was a retrospective cohort study involving manual review of confirmed mpox cases at three large clinical centers in Houston, Texas and New York City, NY. Descriptive statistics were calculated for rates of STI testing and new diagnoses of syphilis, chlamydia and gonorrhea.

There were 404 patients in the cohort from the three different clinical sites. The median age was 33 years. 66% underwent STI testing within two weeks of their mpox diagnosis. Among those who were tested, there were 71 patients with a new STI. Syphilis was the most newly diagnosed STI with 31 new cases. Most of the chlamydia and gonorrhea cases were extragenital (81%). Rates of chlamydia and gonorrhea tended to be higher in patients reporting site-specific symptoms (ex. pharyngitis, urethritis) than in asymptomatic patients. However, rates of STI testing were still low even in patients reporting site-specific symptoms. 63.6% of those reporting urinary symptoms, 51.9% of those reporting rectal symptoms and 47.4% reporting pharyngitis symptoms were tested for site-specific chlamydia and gonorrhea.

Our findings highlight a gap in STI testing even in patients at high risk presenting with mpox, a sexually transmitted infection.