(P475) Trends in and factors associated with having bacterial vaginosis and vulvovaginal candidiasis among women attending the Melbourne Sexual Health Centre, 2012-2021

Background: Bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC) are common vaginal infections that significantly impact a woman’s quality of life. However, current treatments are inadequate for preventing recurrent infections. We aimed to determine the factors associated with BV and VVC to inform clinical care.

Methods: We performed a retrospective audit of BV and VVC positivity and recurrence among women attending the Melbourne Sexual Health Centre between 1st January 2012 and 31st December 2021. The proportions of women with BV and VVC at their first-test during the study period were calculated with 95% confidence intervals(CI). Factors associated with having BV or VVC vs no BV/VVC detected at their first-test were determined using logistic regression, and factors associated with recurrence (defined as >1 infection within 12-months) were assessed using Poisson regression, which accounted for multiple visits. Factors associated with infection positivity or recurrence in univariable analyses were included in multivariable models.

Results: Of 50,245 female attendees, 6,975/22,769 (31%) had BV and 6,587/22,987 (29%) had VVC detected at their first-test. Women reporting hormonal contraceptive-use (excluding intrauterine-device use) were less likely to have BV than women using no hormonal contraception (adjusted-odds-ratio[AOR]=0.73, 95%CI:0.68-0.82, p< 0.0001). Women reporting ≥2 male or ≥1 female partners in the preceding 3 months had higher odds of BV (AOR=1.33, 95%CI:1.23-1.42,p < 0.0001; AOR=1.86, 95%CI:1.50-2.30,p < 0.0001, respectively). Younger women (AOR=1.02, 95%CI:1.02-1.03,p < 0.0001) and those with ≥2 male partners (AOR=1.17, 95%CI:1.09-1.27,p=0.001) had higher odds of VVC. Overall, 1,406 women experienced recurrent BV, and risk of recurrence was higher among women with a regular sexual partner (adjusted-incidence-rate-ratio[AIRR]=1.32,95%CI:1.16-1.50,p < 0.0001) and those using any intrauterine-device (AIRR=1.29, 95%CI:1.07-1.56, p=0.007). 1,169 women experienced recurrent VVC over the decade. Sex workers (AIRR=1.87,95%CI:1.52-2.30,p < 0.0001) and those with concurrent BV (AIRR=1.23,95%CI:1.04-1.45,p=0.016) had a higher risk of recurrent VVC.

Conclusion: BV and VVC were common. BV had a risk profile more commonly associated with STIs, with stronger associations observed between BV and sexual practices compared to VVC. Factors associated with BV or VVC at first-visit and recurrence differed, suggesting individualised therapeutic approaches may promote long-term cure for women. Understanding the key drivers behind these vaginal conditions is integral to improving clinical care and sexual health for women.