Recurrence of bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC) following recommended treatment is common. We aimed to determine the factors associated with BV and VVC and recurrent infections to inform management strategies.
We conducted a retrospective study of BV and VVC infections and recurrence among female Melbourne Sexual Health Centre attendees from 1 January 2012 to 31 December 2021. The proportion with BV and VVC at their first annual test within a calendar year was calculated with 95% CIs. Factors associated with BV or VVC were determined using logistic regression, and factors associated with recurrence (>1 diagnosis within 12 months) were assessed using Poisson regression, accounting for multiple visits.
Of 50 245 attendees, 9343/29 990 (31%) had BV and 8528/30 210 (28%) had VVC at their first annual test; positivity of both increased over time. Women had higher odds of BV if they had >1 male or one or more female partner(s) in the prior 3 months (adjusted OR (aOR)=1.29; 95% CI 1.21 to 1.39; aOR=1.69; 95% CI 1.49 to 1.92, respectively), and lower odds if they used hormonal contraception (aOR=0.73; 95% CI 0.68 to 0.79). Women had higher odds of VVC if they reported >1 male partner in the prior 3 months (aOR=1.11; 95% CI 1.04 to 1.19). The recurrence rate of BV was 22/100 person-years (PY), and risk of BV recurrence was higher among sex workers (adjusted recurrence rate ratio (aRRR)=2.02; 95% CI 1.71 to 2.39), women with a regular sexual partner (RSP; aRRR=1.32; 95% CI 1.16 to 1.50) and intrauterine device (IUD) users (aRRR=1.29; 95% CI 1.07 to 1.56). The recurrence rate of VVC was 17/100 PY, and the risk of recurrence was higher among sex workers (aRRR=2.00; 95% CI 1.55 to 2.59) and those with an RSP (aRRR=1.25; 95% CI 1.06 to 1.46).
BV and VVC rates and recurrence were high among attendees. Both infections were associated with risk factors that support sexual transmissibility of each, while only BV recurrence was associated with IUD use, supporting existing data that IUDs increase a woman’s risk of acquisition and persistence of a suboptimal vaginal microbiota. These data highlight the importance of considering an individual’s partners and contraceptive use when managing these infections.