Correlates of Sexually Transmitted Infection (STI) Positivity and Implementation of Point-of-Care STI Testing at a Mobile Clinic for Women Who Inject Drugs in Seattle, WA.

Abstract

BACKGROUND: Women who inject drugs (WWID) face complex barriers to engagement in sexual healthcare. We used point-of-care (POC) testing to assess sexually transmitted infection (STI) prevalence, correlates, and treatment delivery, as well as testing acceptability and feasibility, at a mobile clinic for WWID in Seattle, Washington. METHODS: We implemented a mobile clinic offering substance use and sexual health services for women ≥18 years with a history of injecting drugs and negative or unknown HIV status. We offered POC testing for trichomonas, syphilis, chlamydia, gonorrhea, and HIV at enrollment, 3-months, and 6-months. Participant surveys assessed demographics, behaviors, and acceptability of POC testing. Provider surveys assessed feasibility of care delivery. We used bivariate analysis to identify correlates of STI positivity. RESULTS: Among 50 WWID enrolled, 73% were unstably housed, and 56% reported a previous STI. In the preceding three months, 34% reported transactional sex, and 38% had ≥2 sexual partners. During the study period, 26% of women tested positive for trichomonas, 4% for syphilis, 3% each for chlamydia and gonorrhea, and 0% for HIV. Same-day treatment was provided in 94% of cases. STI positivity was associated with ≥2 sexual partners (OR 5.8, p = 0.02) and transactional sex (OR 4.8, p = 0.02). POC testing was acceptable, and 84% preferred it over traditional methods. Staff encountered challenges with POC logistics and competing participant priorities. CONCLUSIONS: STI prevalence, particularly trichomonas, was high among WWID, but low-barrier POC STI testing services were acceptable and feasible, leading to same-day STI treatment in most cases.