Thesis (Ph.D.)--University of Washington, 2012 Introduction : Vaginal infections, including bacterial vaginosis (BV), vulvovaginal candidiasis (VVC) and Trichomonas vaginalis (TV), are highly prevalent among reproductive-aged women and are associated with a number of adverse reproductive health outcomes. Interventions that improve vaginal health could have a substantial impact on reproductive health. Methods : Data from women enrolled in a randomized trial of periodic presumptive treatment (PPT) for vaginal infections were used to assess the effect of PPT on: (1) establishing and sustaining a healthy vaginal environment; and (2) BV and Lactobacillus colonization in the 3-month interval following completion of the trial. Data from women enrolled in an open cohort study of female sex workers were used to compare the effect of single-dose 2g oral metronidazole on TV infection in HIV-1-seropositive versus HIV-1-seronegative women. Results : The incidence of a healthy vaginal environment was 608 per 100 person-years in the intervention arm and 454 per 100 person-years in the placebo arm (hazard ratio [HR]=1.36; 95% confidence interval [CI] 1.17-1.58). Sustained vaginal health (healthy vaginal environment for ≥ 3 consecutive visits) was also more frequent in the intervention arm (HR=1.69; 95% CI 1.23-2.33). The post-trial incidence of BV was 260 per 100 person-years in the intervention arm versus 358 per 100 person-years in the placebo arm (HR=0.76; 95% CI 0.51-1.12). The post-trial incidence of Lactobacillus colonization was 180 per 100 person-years in the intervention arm versus 127 per 100 person-years in the placebo arm (HR=1.42; 95% CI 0.85-2.71). There were 42 of 282 (15%) persistent infections among HIV-seropositive women versus 35 of 288 (12%) among HIV-seronegative women (adjusted odds ratio [aOR]=1.26; 95% CI 0.75-2.12). TV infection with concurrent BV by Gram stain was associated with an increased likelihood of persistent TV (aOR=1.82; 95% CI 1.11-2.99). Conclusions : Periodic presumptive treatment is effective at establishing and sustaining a healthy vaginal environment. However, its effect on BV and Lactobacillus colonization was not sustained after cessation of the intervention. The frequency of persistent TV following treatment with single-dose metronidazole was similar by HIV-1 status. Alternative regimens may be necessary to improve cure rates for women with TV and concurrent BV
