Geographic correlates of primary and secondary syphilis among men who have sex with men in the United States.

Purpose: Primary and secondary (P&S) syphilis in men who have sex with men (MSM) has been increasing; however, there is a lack of research on geographic factors associated with MSM P&S syphilis.

Methods: We used multiple data sources to examine associations between social and environmental factors and MSM P&S syphilis rates at the state- and county-level in 2014 and 2015, separately. General linear models were used for state-level analyses, and hurdle models were used for county-level models. Bivariate analyses (P < .25) were used to select variables for adjusted models.

Results: In 2014 and 2015 state models, a higher percentage of impoverished persons (2014 β = 1.24, 95% confidence interval, 0.28-2.20; 2015 β = 1.19; 95% confidence interval, 0.42-1.97) was significantly associated with higher MSM P&S syphilis rates. In the 2015 county model, policies related to sexual orientation (marriage, housing, hate crimes) were significant correlates of MSM P&S syphilis rates (P < .05).

Conclusions: Our state-level findings that poverty is associated with MSM P&S syphilis are consistent with research at the individual level across different subpopulations and various sexually transmitted diseases. Our findings also suggest that more research is needed to further evaluate potential associations between policies and sexually transmitted diseases. Geographic-level interventions to address these determinants may help curtail the rising syphilis rates and their sequelae in MSM.