Introduction Pregnant women - In the US, Congenital Syphilis (CS) rates have increased 48% between 2012 and 2015. We explored county level sociodemographic factors associated with having reported at least one CS case during 2012 and 2015 among all US counties.

Methods The 321 (10.2%) US counties that reported at least 1 CS case during 2012–2015 were compared to the remaining 2829 (89.8%) US counties with no reported CS. Multivariable logistic regression models were constructed to assess factors independently associated with counties reporting CS using adjusted Odds Ratios (aOR). County level factors examined included:% population black [above or below the national median],% Hispanic population [above or below the national median], Medicaid expansion state, violent crime rate per 100,000, and the% change in adult male and female syphilis cases between during 2012 and 2015. Final models were determined by comparing likelihood ratio statistics.

Results Independent county level factors associated with reporting at least one CS case during 2012–2015 were: Medicaid expansion state [aOR=2.24, 95% CI 1.51–3.34],% black population [aOR=2.86,95% CI 1.79–4.57],% Hispanic [aOR=2.13, 95% CI 1.41–3.24], 10 unit change in violent crime rate [aOR=1.04, 95% CI 1.02–1.05], and 10 unit change in% change in female syphilis [aOR=1.02, 95% CI 1.00–1.03].

Conclusion CS in the US is highly geographically focused with only 10.2% of counties reporting any cases in the past 4 years. Socioeconomic and demographic factors working at the community level are associated with increased odds of having reported a case of CS. Interventions to prevent CS in the US should focus at community, as well as individual level.