(P416) Trends in Primary and Secondary Syphilis among Females in Chicago, 2017-2021

Background: Between 2017 and 2021 total number of primary and secondary syphilis (P&S) cases in females increased by 198% between (from 55 to 164 cases). These increases are concerning because of the likelihood of transmission of syphilis during pregnancy. The objective of the analysis was to identify any new trends or risk factors identified among females diagnosed with P&S Syphilis.



Methods: Syphilis surveillance data reported to the Chicago Department of Public Health (CDPH) were analyzed using SAS version 9.4. All syphilis cases were reviewed and met the CDC case definitions for P&S syphilis.



Results: Between 2017 and 2021, cases among females increased across all race/ethnicities: non-Hispanic Blacks increased by 224% (34 to 110), non-Hispanic Whites increased by 650% (2 to 15), Hispanics increased by 950% (2 to 21), and other/unknown increased by 6% (17 to 18). The median age at delivery was 28 (IQR=14). Cases across all age groups increased with the highest increases in 13-19 (500%), 40-49 (286%), and 30-39 (218%). Pregnant cases increased 200% (2 to 12).



During the same time period, the number of P&S syphilis cases among females co-infected with HIV decreased by 33% (9 to 6) but the number of cases with a history of STD infections increased by 320% (10 to 42). The average number of reported sex partners was 1 (IQR=1). Total number of females with P&S syphilis reporting having sex with anonymous partners increased by 71% (7 in 2017 to 12 in 2021) while in 2019, 18 females and 31 females reported having anonymous sex in 2020.



Conclusion As the number of P&S syphilis cases among females increased, the trends in demographics and risk behavior were changing. Although most cases were among non-Hispanic Blacks, we saw increases across all races/ethnicities. Highest increases were reported among individuals in the age group 13- 29 years old. As P&S cases increase, it is important that local health departments work closely not only with clinical providers but community partners to develop targeted interventions for these populations.