Group B streptococcus: prevalence in a non-obstetric population

J Low Genit Tract Dis. 2010 Jul;14(3):162-6. doi: 10.1097/LGT.0b013e3181d3d40f.


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

Materials and methods: 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.

Results: 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.

Conclusions: 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.

MeSH terms

  • Adolescent
  • Adult
  • Cross-Sectional Studies
  • Female
  • Humans
  • Middle Aged
  • Prevalence
  • Streptococcal Infections / epidemiology*
  • Streptococcal Infections / microbiology*
  • Streptococcus agalactiae / isolation & purification*
  • Vagina / microbiology
  • Vaginitis / epidemiology*
  • Vaginitis / microbiology*
  • Young Adult