Vaginal anaerobes are associated with cervicitis: A case-control study

Cervicitis is associated with important reproductive sequelae. Primary causes include chlamydia and gonorrhoea, but a known sexually transmitted infection (STI) is not identified in >50% of cases (i.e. STI-negative cervicitis). Bacterial vaginosis (BV) and specific BV-associated bacteria have also been associated with cervicitis, but data are limited. We investigated the association between STI-negative cervicitis and vaginal microbiota composition.

This was a case-control sub-study of the OhMG study conducted at the Melbourne Sexual Health Centre. Cases were women with cervicitis who tested negative for STIs (STI-negative cervicitis, n = 64). Controls were STI-negative asymptomatic women attending for STI-screening (n = 128). The vaginal microbiota was characterised using 16S rRNA gene sequencing. Vaginal community state types were compared between cases and controls using logistic regression. Differential abundance analysis was performed to identify taxa associated with STI-negative cervicitis.

STI-negative cervicitis cases were more likely than controls to have a Lactobacillus-deficient non-optimal microbiota (adjusted-odds-ratio 2.55, 95% CI 1.18-5.50). Compared to controls, cases had increased abundance of four BV-associated bacteria (Gardnerella, Fannyhessea vaginae, Prevotella bivia, Dialister micraerophilus) and decreased abundance of optimal lactobacilli.

We report a positive association between non-optimal vaginal microbiota composition and STI-negative cervicitis. Specific anaerobic BV-associated bacteria may represent infectious causes of cervicitis.