Background Trichomonas vaginalis is the most prevalent curable sexually transmitted infection in the United States and may lead to preterm delivery, infertility and increased HIV transmission. Illicit drug use, HIV infection and Black race have been associated with high rates of infection. Incarcerated women may be at especially high risk for infection, though few studies have examined routine screening for trichomonas in this population.

Methods Women >18-years-old entering the Rhode Island Department of Corrections between September 2009 and December 2010 were recruited to participate. All women submitted a self-collected vaginal swab for trichomonas culture and Transcription Mediated Amplification testing. Each participant completed a survey addressing demographics, symptoms, sexual behaviour, and substance use by audio computer-assisted self-interview. Data analysis was completed using multivariate logistic regression in STATA.

Results 288 women enrolled in the study, mean age was 28 years. 59% of participants were White, 17% Hispanic, 12% Black and 12% other races. Forty-three per cent reported vaginal symptoms and 54% reported illicit drug use in the 30 days prior to incarceration. Among all participants, the prevalence of trichomonas was 8.7% by culture and 12.5% by NAAT. The strongest predictors of infection included Black race (OR 4.1, 95% CI 1.4 to 12.0), cocaine use in the 30 days prior to incarceration (OR 2.5, 95% CI 1.1 to 5.7), and >3 year since last pap smear (OR 5.2, 95% CI 1.5 to 17.8). Vaginal symptoms and age were not significantly associated with trichomonas detection.

Conclusions Trichomonas infection is common in incarcerated women, especially among Blacks, recent cocaine users and those not receiving routine gynaecologic care. Infection was not predicted by symptoms or by age. Routine screening for trichomonas infection in high-risk populations may lead to increased detection and treatment.