High recurrence rates of bacterial vaginosis over the course of 12 months after oral metronidazole therapy and factors associated with recurrence

Abstract

Background: We wished to determine recurrences of bacterial vaginosis (BV) after treatment over the course of 12 months and to establish factors associated with recurrence.

Methods: Women with symptomatic BV (a Nugent score [NS] of 7-10 or of 4-6 with >or=3 Amsel criteria) were enrolled. BV was treated with 400 mg of oral metronidazole twice a day for 7 days. Participants completed a questionnaire and vaginal swabs were collected at 1, 3, 6, and 12 months; the study end point was an NS of 7-10.

Results: A total of 121 (87%) women with an NS of 7-10 and 18 (13%) with an NS of 4-6 and >or=3 Amsel criteria were enrolled; 130 (94%) returned >or=1 vaginal samples. Sixty-eight women (58% [95% confidence interval {CI}, 49%-66%]) had a recurrence of BV (NS 7-10), and 84 (69% [95% CI, 61%-77%]) had a recurrence of abnormal vaginal flora (NS 4-10) by 12 months. A past history of BV, a regular sex partner throughout the study, and female sex partners were significantly associated with recurrence of BV and abnormal vaginal flora by multivariate analysis; the use of hormonal contraception had a negative association with recurrence.

Conclusion: Current recommended treatment is not preventing the recurrence of BV or abnormal vaginal flora in the majority of women; factors associated with recurrence support a possible role for sexual transmission in the pathogenesis of recurrent BV.