The Role of Jail Testing in the Public Health Response to Syphilis in King County, Washington.

Abstract: Background: The incidence of syphilis among cisgender women and heterosexual men in the U.S. has risen sharply. Public Health - Seattle & King County (PHSKC) implemented a voluntary, opt-in syphilis screening program in a jail to reach disproportionately affected populations outside the healthcare system.Methods: PHSKC Disease Intervention Specialists (DIS) conducted syphilis screening four days per week in a regional jail. All persons screened January 2022 - March 2023 were included in the analysis. DIS performed point-of-care treponemal-specific tests, collected demographic and risk factor data, worked with jail medical providers to coordinate empiric treatment and confirmatory testing, and determined syphilis history and stage. We categorized persons with reactive rapid tests as "confirmed", "presumed", "possible", or "not new" cases based on confirmatory testing and syphilis history. We compared the characteristics of confirmed cases to overall King County syphilis cases using chi-square tests and examined treatment completion by diagnosis category.Results: 1,371 persons completed screening; 69 (5.0%) had positive results, of whom 51 (73.9%) had confirmatory testing, and 33 had confirmed infections (2.4% of screened persons). Compared to all King County syphilis cases, confirmed cases were more likely to be cisgender women (30.3% vs. 21.9%) or cisgender heterosexual men (66.7% vs. 20.6%), people living homeless (66.7% vs. 24.3%), or people who use methamphetamine (90.9% vs 20.3%) (p < 0.001 for all comparisons). Among 33 persons with confirmed syphilis, 29 (87.8%) started and 18 (54.5%) completed treatment.Conclusions: Jail screening reached persons at disproportionate risk for syphilis, but treatment was often incomplete.