Incidence and predictors of reinfection with trichomoniasis based on nucleic acid amplification testing results in HIV-infected patients.

Trichomonas vaginalis infection contributes to HIV transmission. The study objective was to determine the incidence and predictors of T. vaginalis reinfection among HIV-infected women in Birmingham, Alabama. A retrospective cohort study of women at an urban HIV clinic from August 2014 to March 2016 with T. vaginalis by nucleic acid amplification test (NAAT) was conducted. Time to first episode of reinfection was evaluated using Kaplan-Meier survival curves. The association of various predictors was evaluated by univariate and multivariable Cox proportional hazards analyses. Of 612 HIV-infected women at the UAB HIV clinic tested for T. vaginalis by the Aptima TV assay, 110 (18.0%) were identified with prevalent T. vaginalis infection. Overall, 25/110 (22.7%) had a first episode of T. vaginalis reinfection by NAAT with a rate of 3.7 reinfections per 100 person-months (95% confidence interval [CI]: 2.3, 5.2). In univariate analysis, only an HIV viral load (VL) ≥200 copies/ml approached statistical significance (hazard ratio = 2.26; 95% CI: 0.97, 5.29, p = 0.06). After adjusting for age and race, the association of HIV VL ≥200 copies/ml remained strong (adjusted hazard ratio = 2.49; 95% CI: 0.99, 6.27, p = 0.05). T. vaginalis reinfection was high among HIV-infected women in this sample, necessitating enhanced disease control efforts in this high-risk population.