Introduction CDC recommends syphilis screening at least annually for sexually active MSM and screening every 3–6 months for MSM with risks such as multiple partners.

Methods In collaboration with a large U.S. commercial laboratory, we identified men aged 15–60 years who had rectal chlamydia (CT) or gonorrhoea (GC) testing during September, 2013-Augest, 2015 as presumed MSM. We estimated: the frequency of testing (counting only tests≥3 months after a previous test); reactivity of nontreponemal tests (NTT) and treponemal tests (TT); and the association between CT/GC and the reactivity of syphilis NTT and TT. We also identified the number of the men with documented as primary, secondary, or early latent syphilis (PSELS) by ICD_9 codes.

Results Of 52,771 MSM, 33.8% were aged 15–29 years, 89.6% had private insurance, 51.0% resided in South, and 74.8% had tests ordered by infectious disease specialists. 14.5% had no syphilis tests, 4.8% had TT only (38.2% were reactive), 63.0% had NTT only (2.0% were reactive), and 17.7% had both NTT and TT (8.3% neither were reactive and 86.4% both were reactive). Of 45,108 MSM who had syphilis tests, 1.1% had PSELS. Of 2,547 MSM who had TT only, the number of tests in the two years was one (57.1%), two (22.3%), and three (13.3%). Of 33,238 MSM who had NTT only, the number of tests was one (53.5%), two (23.3%), and three (11.1%). Of 9323 MSM who had both NTT and TT, the number of tests was one (30.4%), two (24.7%), three (17.8%), and four (12.8%). Of 11 870 men who had reactive TT, 51.8% had ≥two reactive TT. CT and GC were significantly higher in men with reactive vs. nonreactive NTT and TT: rectal CT (24.4% vs. 12.6%) or GC (19.8% vs. 9.9%); pharyngeal CT (5.4% vs. 2.9%) or GC (14.7% vs. 10.6%); urethral CT (7.6% vs. 5.7%) or GC (8.0% vs. 5.3%).

Conclusion Syphilis testing was common among men who were tested for rectal CT or GC, but most were tested only once. Men with reactive syphilis tests were more likely to have GC or CT vs. men with nonreactive tests. Routine and timely syphilis testing should be prioritised.