The influence of the vaginal ecosystem on vaginitis, bacterial vaginosis, and sexually transmitted diseases: an epidemiological study and literature review

Purpose: This study aimed to demonstrate the correlation between altered balance of the vaginal ecosystem and increased risk of vaginitis, bacterial vaginosis, and sexually transmitted diseases and the association between specific alterations found in fresh bacterioscopic examinations (FBE) and the risk of certain infections. Methods: A retrospective, monocentric study was conducted from January 2013 to December 2023. Patients who underwent FBE and vaginal swabs following reported symptoms or suspected syndromic pictures of vulvovaginal infections were included. Results: Two thousand one hundred ten patients were included and divided into a control group (n = 811, 38.4%) and a pathological group (n = 1299 patients, 61.6%), based on the presence of alterations at the FBE. In the pathological group, 1185 women (91% of positive FBE) had vaginal infections detected through vaginal swabs. The presence of lactobacilli and typical inflammatory cells was detected in 111 (8%) women with pathological FBE and correlated with higher rates of positive swabs for common germs (n = 104, 94%), often leading to co-infections (n = 30, 29%). Conversely, Döderlein’s cytolysis (n = 56, 4.3% of positive FBE) indicated a predominance of positive human papillomavirus (HPV) swabs (n = 33, 59%). The presence of fungal elements (n = 208, 16% of positive FBE) suggested a higher prevalence of co-infections (n = 62, 30%). Similarly, mixed bacterial flora (n = 470, 36% of positive FBE) and Trichomonas vaginalis (n = 11, 0.8% of positive FBE) correlated with positive swabs for other pathogens, except for Mycoplasma (n = 0). Bacterial vaginosis (n = 443, 34% of positive FBE) was linked to co-infections (n = 142, 32%) and HPV (n = 123, 28%). Conclusion: The importance of conducting FBE in patients with vulvovaginal symptoms is emphasized. This approach aids in determining the need for further diagnostic tests like vaginal swabs, guided by microscopic findings. A strong correlation emerges between the presence of specific alterations in the FBE and an increased prevalence of certain infections.