Group B streptococcus: prevalence in a non-obstetric population

To establish and compare the prevalence of group B streptococcus (GBS) colonization in the vaginas of nonobstetric women with and without vaginitis.

Cross-sectional analysis GBS vaginal culture status of nonpregnant, estrogen-replete women 18 years or older presenting for annual gynecological examinations or vaginal infection. Subjects were classified into 3 groups: no vaginitis if symptoms were absent and examination results was normal; common vaginitis (CV) if microscopic examination revealed yeast, bacterial vaginosis, or trichomonads; or inflammatory vaginitis (IV) if examination revealed inflammation and immature squamous cells but no pathogens.

Of the 215 women recruited, 147 (68.4%) showed no evidence of vaginitis, 41 (19.1%) had CV, and 27 (12.6%) showed evidence of IV. The overall prevalence rate of GBS was 22.8%. Vaginitis was associated with a significantly increased risk of GBS colonization (adjusted odds ratio: CV = 2.7, 95% CI = 1.1-6.2; IV = 2.9, 95% CI = 1.1-8.0). Logistic regression revealed pH higher than 4.5, presence of abnormal discharge on examination, and a women's complaint of current symptoms as significant predicators of the presence of GBS.

Group B streptococcus colonization occurs more commonly in women with vaginitis. This suggests that disruption of the normal vaginal bacterial environment is an important predictor for GBS colonization.