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Background: The association between vaginal washing and HIV risk may be mediated by vaginal washing-associated changes in vaginal microbiota., Methods: Data from a cohort of HIV-negative US and Kenyan women enrolled in the Preventing Vaginal Infections trial were analyzed. Vaginal fluid samples and vaginal washing data were collected every 2 months for 12 months. Bacterial relative abundances were measured by broad-range 16S rRNA gene polymerase chain reaction with next generation sequencing. Generalized estimating equations were used to evaluate the association between vaginal washing and i) the Shannon Diversity Index (SDI); and ii) mean change in percent bacterial relative abundances, with application of a 10% false discovery rate (FDR)., Results: Participants ( N = 111) contributed 93/630 (14.8%) vaginal washing visits. Mean SDI was 0.74 points higher (95% CI 0.35, 1.14; p < 0.001) at washing visits among US participants ( N = 26). Vaginal washing was not associated with SDI in Kenyan participants ( N = 85). There were no associations between vaginal washing and vaginal bacterial relative abundances after applying the FDR., Conclusions: The discordant results in Kenyan versus US women suggests the link between vaginal washing and sub-optimal vaginal microbiota may be context specific. Vaginal microbial shifts may not fully explain the association between vaginal washing and HIV acquisition.

Vaginal washing is a common practice associated with adverse outcomes including bacterial vaginosis (BV) and HIV infection. Prior studies have not examined the associations between vaginal washing and individual vaginal bacteria, or whether these associations are independent of the effect of vaginal washing on BV. The purpose of this study was to characterize the association between vaginal washing and the presence and concentrations of vaginal bacteria associated with optimal and sub-optimal vaginal states. The analysis utilized data from participants in the placebo arm of the Preventing Vaginal Infections trial, which enrolled HIV-uninfected women from the United States and Kenya. Detection of bacterial taxa associated with BV was compared between visits with versus without reported vaginal washing. The effect of vaginal washing on a number of vaginal bacteria differed substantially (p<0.05) between the US and Kenya, so results were stratified by country. In US women, vaginal washing was associated with a significantly higher likelihood of detection of BV associated bacterium 1 (BVAB1) (relative risk [RR] 1.55, 95% confidence interval [CI] 1.15-2.09, p = 0.004), BVAB2 (RR 1.99, 95%CI 1.46-2.71, p<0.001), Mageeibacillus indolicus (RR 2.08, 95%CI 1.46-2.96, p<0.001), Atopobium vaginae (RR 1.34, 95%CI 1.13-1.59, p = 0.001), Leptotrichia/Sneathia species (RR 1.66, 95% CI 1.33-2.09, p<0.001), Megasphaera species (RR 1.78, 95%CI 1.34-2.37, p<0.001) and Gardnerella vaginalis (RR 1.08, 95%CI 1.01-1.16, p = 0.02). No significant association between vaginal washing and bacterial detection was found in Kenyan women. Adjustment for bacterial vaginosis diagnosed by Gram stain did not alter these results. This study provides evidence that the association between vaginal washing and detection of individual bacterial taxa can vary regionally. For some vaginal bacteria, the association with vaginal washing may be independent of the effect on Gram stain detection of BV. Larger prospective studies in diverse geographic settings should explore whether eliminating vaginal washing impacts the presence and concentrations of key vaginal bacteria., Competing Interests: RSM receives research funding, paid to the University of Washington, from Hologic Corporation. All other authors reported no conflicts of interest. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Background: Little is known about the natural history of Mycoplasma genitalium (MG) infection in women. We retrospectively tested archived vaginal fluid samples to assess MG prevalence, incidence, persistence, recurrence and antimicrobial resistance markers among women participating in the Preventing Vaginal Infections trial, a randomized trial of monthly presumptive treatment to reduce vaginal infections., Methods: High-risk, nonpregnant, HIV-negative women aged 18 to 45 years from Kenya and the United States were randomized to receive metronidazole 750 mg + miconazole 200 mg intravaginal suppositories or placebo for 5 consecutive nights each month for 12 months. Clinician-collected swabs containing cervicovaginal fluid were tested for MG using Hologic nucleic acid amplification testing at enrollment and every other month thereafter. Specimens that were MG+ underwent additional testing for macrolide resistance-mediating mutations by DNA sequencing., Results: Of 234 women enrolled, 221 had available specimens and 25 (11.3%) had MG at enrollment. Among 196 women without MG at enrollment, there were 52 incident MG infections (incidence, 33.4 per 100 person-years). Smoking was independently associated with incident MG infection (adjusted hazard ratio, 3.02; 95% confidence interval, 1.32-6.93), and age less than 25 years trended toward an association (adjusted hazard ratio, 1.70; 95% confidence interval, 0.95-3.06). Median time to clearance of incident MG infections was 1.5 months (interquartile range, 1.4-3.0 months). Of the 120 MG+ specimens, 16 specimens from 15 different women were macrolide resistance-mediating mutation positive (13.3%), with no difference by country., Conclusions: M. genitalium infection is common among sexually active women in Kenya and the Southern United States. Given associations between MG and adverse reproductive health outcomes, this high burden of MG in reproductive-aged women could contribute to substantial morbidity.

Background: Bacterial vaginosis (BV) may increase women's susceptibility to sexually transmitted infections (STIs). In a randomized trial of periodic presumptive treatment (PPT) to reduce vaginal infections, we observed a significant reduction in BV. We further assessed the intervention effect on incident Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium infection., Methods: Nonpregnant, human immunodeficiency virus-uninfected women from the United States and Kenya received intravaginal metronidazole (750 mg) plus miconazole (200 mg) or placebo for 5 consecutive nights each month for 12 months. Genital fluid specimens were collected every other month. Poisson regression models were used to assess the intervention effect on STI acquisition., Results: Of 234 women enrolled, 221 had specimens available for analysis. Incidence of any bacterial STI (C. trachomatis, N. gonorrhoeae, or M. genitalium infection) was lower in the intervention arm, compared with the placebo arm (incidence rate ratio [IRR], 0.54; 95% confidence interval [CI], .32-.91). When assessed individually, reductions in STI incidences were similar but not statistically significant (IRRs, 0.50 [95% confidence interval {CI}, .20-1.23] for C. trachomatis infection, 0.56 [95% CI, .19-1.67] for N. gonorrhoeae infection, and 0.66 [95% CI, .38-1.15] for M. genitalium infection)., Conclusions: In addition to reducing BV, this PPT intervention may also reduce the risk of bacterial STI among women. Because BV is highly prevalent, often persists, and frequently recurs after treatment, interventions that reduce BV over extended periods could play a role in decreasing STI incidence globally., (© The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.)