Background During 2011–2015, approximately half (48% to 53%) of reported primary and secondary (P&S) syphilis cases occurred among men who have sex with men (MSM) with diagnosed HIV. However, comparing rates of reported P&S syphilis by HIV status among MSM requires MSM population denominators stratified by HIV status.

Methods We used previously published state-level estimates of the MSM population and publicly available data on diagnosed HIV infection among MSM to determine population denominators of MSM living with or without diagnosed HIV infection. We then examined rates of reported P&S syphilis per 100,000 MSM by HIV status using national case-based surveillance data in 24 states with ≥70% complete reporting of sex of sex partners and HIV status among syphilis cases during 2011–2015.

Results During 2011–2015, rates of reported P&S syphilis among MSM in the 24 states included in the analysis increased 45% (188.7 to 272.8 per 100,000). Concurrently, rates among HIV-negative and HIV-unknown MSM, combined, increased 64% (83.0 to 136.5 per 100,000), while rates among MSM with diagnosed HIV increased 17% during 2011–2014 (1,061.5 to 1,237.3 per 100,000) before decreasing 6% to 1,229.5 in 2015. Rate ratios comparing reported P&S syphilis rates among MSM living with diagnosed HIV to HIV-negative and HIV-unknown MSM decreased annually during this period from 12.8 to 9.0.

Conclusion During the most recent five-year period for which data are available, rates of reported P&S syphilis increased among MSM diagnosed with HIV, as well as MSM not diagnosed with HIV. Although rates are higher among MSM diagnosed with HIV, larger relative increases in rates among MSM not diagnosed with HIV and subsequent declining rate ratios indicated that differences between MSM with diagnosed HIV and HIV-negative or HIV-unknown MSM diminished over time.

Disclosure No significant relationships.