Efficacy of Oral Metronidazole with Vaginal Clindamycin or Vaginal Probiotic for Bacterial Vaginosis: Randomised

Background: To determine if oral metronidazole (MTZ-400mg bid) with 2 % vaginal clindamycin-cream (Clind) or a Lactobacillus acidophilus vaginal-probiotic containing oestriol (Prob) reduces 6-month bacterial vaginosis (BV) recurrence. Methods: Double-blind placebo-controlled parallel-group single-site study with balanced randomization (1:1:1) conducted at Melbourne Sexual Health Centre, Australia. Participants with symptomatic BV [Nugent Score (NS) = 7–10 or $3 Amsel’s criteria and NS = 4–10], were randomly allocated to MTZ-Clind, MTZ-Prob or MTZ-Placebo and assessed at 1,2,3 and 6 months. MTZ and Clind were administered for 7 days and Prob and Placebo for 12 days. Primary outcome was BV recurrence (NS of 7–10) on self-collected vaginal-swabs over 6-months. Cumulative BV recurrence rates were compared between groups by Chi-squared statistics. Kaplan-Meier, log rank and Cox regression analyses were used to compare time until and risk of BV recurrence between groups. Results: 450 18–50 year old females were randomized and 408 (91%), equally distributed between groups, provided $1 NS post-randomization and were included in analyses; 42 (9%) participants with no post-randomization data were excluded. Six-month retention rates were 78 % (n = 351). One-month BV recurrence (NS 7–10) rates were 3.6 % (5/140), 6.8 % (9/133