Bacterial vaginosis is uncommon in women who are virgins. We estimated effects of sexual debut on vaginal bacterial colonization.
Women who were virgins and aged 18–22 enrolled in a study of human papillomavirus acquisition were followed every 4 months for up to 2 years. Vaginal swabs from before and after sexual debut, or two independent visits for those remaining virginal were tested by quantitative polymerase chain reaction for Lactobacillus crispatus, L. jensenii, L. iners, Gardnerella vaginalis, and the bacterial vaginosis-associated species Atopobium vaginae, Megasphaera spp., Leptotrichia spp, Sneathia, spp BVAB1, BVAB2, and BVAB3.
We evaluated 97 women: 71 who became sexually active and 26 who remained virginal. At first sampling, 22/26 (85%) of women who remained virginal were colonized with Lactobacillus species compared to 22/26 (85%) at follow-up (p > 0.99). G. vaginalis was present in 12/26 (46%) initially, and 11/26 (42%) at follow-up (p > 0.99). Among women who became sexually active, colonization with Lactobacillus species remained stable: 65/71 (92%) vs. 66/71 (93%) (p > 0.99), while colonization with G. vaginalis increased [28/71 (39%) vs 40/71 (56%); p = 0.02]. Among women who did not initiate sexual activity during the study, 2/26 (8%) had any bacterial vaginosis-associated species detected at both the first and second visits(p > 0.99). Among women who became sexually active during the study 15/71 (21%) were colonized with bacterial vaginosis-associated species initially, compared to 13/71 (18%) after sexual debut (p = 0.77).
Among women who were virgins, vaginal colonization with bacterial vaginosis-associated bacterial species is uncommon and does not change after sexual debut.