Characterization of vaginal flora and bacterial vaginosis in women who have sex with women.

Bacterial vaginosis (BV) may be common among women who report having sex with women (WSW) and frequently occurs in both members of monogamous couples. The results of Gram staining of a vaginal smear were consistent with BV in 81 (25%) and intermediate in 37 (11%) of 326 WSW included in this study. Lactobacilli were detected in 64% of subjects, and 42% of subjects had H(2)O(2)-producing strains. BV was associated with a higher lifetime number of female sex partners, failure to always clean an insertive sex toy before use, and oral-anal sex with female partners. Neither recent douching nor sexual practices with male partners were associated with BV. Vaginal smears from each partner were concordant in 55 (95%) of 58 monogamous couples; BV was present in both partners in 16 couples (28%) (P<.001, compared with expected distribution). BV was common among subjects who did not douche, who did not have concurrent sex with male partners, or who did not have a new sex partner, which suggests that other risk factors for BV exist. These data support the hypothesis that sexual exchange of vaginal secretions is a possible mechanism for acquisition of BV.