The following is a summary of “Bacterial vaginosis and spontaneous clearance of urogenital chlamydia trachomatis in the longitudinal study of vaginal flora,” published in the FEBRUARY 2023 issue of Obstetrics and Gynecology by Brown S, et al.

Although processes were unknown, spontaneous clearance of urogenital Chlamydia trachomatis can happen in 16–44% of patients without treatment. Through influencing immunological responses, epithelial cell proliferation, and chlamydia growth, the vaginal microbiota may assist clearance. For a study, researchers sought to investigate whether bacterial vaginosis (BV) is associated with Chlamydia trachomatis persistence versus spontaneous clearance.

The Longitudinal Study of Vaginal Flora was conducted between 1999-2002 and followed 3,620 reproductive-age women every three months for one year. Chlamydia screening was eventually introduced, and endocervical samples collected earlier in recruitment were tested after study completion. Chlamydia clearance/persistence was evaluated between consecutive visits without chlamydia-active antibiotics. A total of 432 participants and 632 chlamydia case visits were included in the analysis. The association between Nugent score (0-3, no BV; 4-10, intermediate/BV), Amsel-BV, and chlamydia persistence versus clearance were modeled with alternating logistic regression. Participants who experienced clearance and persistence were assessed as their controls using conditional logistic regression.

Of the 632 chlamydia cases, 49% (311/632) spontaneously cleared by the next visit. Participants with intermediate/BV scores had higher odds of chlamydia persistence versus clearance at the next visit than those without BV, controlling for age, contraception, condom use, and marital status. The adjusted odds ratio was 1.84 (95% CI: 1.27-2.69) for Nugent score and 1.32 (95% CI: 0.94-1.84) for Amsel-BV. Adjusting for symptoms did not affect the results. Among participants contributing both persistent and clearance events, intermediate/BV scores were associated with 3-fold higher odds of chlamydia persistence (95% CI: 1.11-9.99).

The study found that bacterial vaginosis was associated with a greater likelihood of untreated chlamydia persisting. It suggested that optimizing the vaginal microbiota may promote chlamydia clearance.

Reference: ajog.org/article/S0002-9378(22)00994-2/fulltext