title: Risks for acquisition of bacterial vaginosis among women who report sex with women: a cohort study.
abstract: BACKGROUND
  Bacterial vaginosis (BV) is common in women who have sex with women. While cross-sectional data support a role for sexual transmission, risks for incident BV have not been prospectively studied in this group.
  
  
  RESULTS
  We studied risks for BV acquisition in a prospective cohort study of women (age 16-35 years) who reported sex with other women (>or=1 partner, prior year). Women were followed for one year with examinations at quarterly visits and for genital symptoms at any time. Species-specific 16S rRNA gene PCRs for BV-associated bacteria (BVAB) were applied to vaginal fluid obtained at enrollment. Sexual behaviors were ascertained by computer-assisted interview. Of 335 participants, 239 had no BV at baseline; 199 were seen in follow-up (median follow-up 355 days, 4.0 visits/subject). Forty women experienced >or=1 BV episode. Risks for incident BV were presentation <or=14 days since onset of menses (hazard ratio (HR) 2.3 (95% CI, 1.2-4.7), report of new sex partner with BV history (HR 3.63 (1.1-11.9)), change in vaginal discharge (HR 2.6 (1.3-5.2)) and detection of any of several BVAB in vaginal fluid at enrollment, including BVAB1 (HR 6.3 (1.4-28.1)), BVAB2 (HR 18.2 (6.4-51.8)), BVAB3 (HR 12.6 (2.7-58.4)), G. vaginalis (HR 3.9 (1.5-10.4)), Atopobium vaginae (HR 4.2 (1.9-9.3)), Leptotrichia spp (9.3 (3.0-24.4)), and Megasphaera-1 (HR 11.5 (5.0-26.6)). Detection of Lactobacillus crispatus at enrollment conferred reduced risk for subsequent BV (HR 0.18 (0.08-0.4)). Detailed analysis of behavioral data suggested a direct dose-response relationship with increasing number of episodes of receptive oral-vulvovaginal sex (HR 1.02 (95% CI, 1.00-1.04).
  
  
  CONCLUSIONS
  Vaginal detection of several BVAB in BV-negative women predicted subsequent BV, suggesting that changes in vaginal microbiota precede BV by weeks or months. BV acquisition was associated with report of new partner with BV; associations with sexual practices - specifically, receptive oral sex - require further investigation.
authors.affiliation: Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America. jmm2@uw.edu
authors.forename: Jeanne M
authors.initials: JM
authors.lastname: Marrazzo
authors.forename: Katherine K
authors.initials: KK
authors.lastname: Thomas
authors.forename: Tina L
authors.initials: TL
authors.lastname: Fiedler
authors.forename: Kathleen
authors.initials: K
authors.lastname: Ringwood
authors.forename: David N
authors.initials: DN
authors.lastname: Fredricks
mesh_terms: D000293:Adolescent; D000328:Adult; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D015331:Cohort Studies; D005260:Female; D018452:Homosexuality, Female; D006801:Humans; D015995:Prevalence; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012747:Sexual Partners; D016585:Vaginosis, Bacterial / Q000453:epidemiology* / Q000382:microbiology
chemical_list: D012336:RNA, Ribosomal, 16S