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. 1997;5(5):336–340. doi: 10.1155/S1064744997000586

Statistical Models for Vaginal Microflora: Identifying Women at Risk for Group B Streptococcus Colonization as a Test of Concept

Mei-Ling T Lee 1,2,, Robin A Ross 1, Andrew B Onderdonk 1
PMCID: PMC2364583  PMID: 18476181

Abstract

Objective: The purpose of this study was to formulate a statistical model that relates human microflora to probabilities for vaginal colonization by group B Streptococcus (GBS).

Methods: Longitudinal observations of total bacterial concentrations at various times during the menstrual cycle were obtained from overtly healthy, non-pregnant, menarcheal women. During each menstrual period and at appropriate intermenstrual times, the duplicate swab technique was used to sample the vaginal vault to obtain microbiologic samples. Women were identified as being colonized with GBS if their samples contained faculative gram-positive cocci. The method of generalized estimating equation (GEE) was used to model the longitudinal data set.

Results: Concentrations of Corynebacterium sp., Streptococcus spp., and total anaerobic bacteria were found to be risk factors for GBS colonization. The sensitivity of the predictive model is 84% and the specificity is 79%.

Conclusions: Although vaginal cultures for GBS are routinely performed to detect colonization, the statistical model described identifies associated risk factors which may be important determinants for GBS colonization.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Anthony B. F., Okada D. M., Hobel C. J. Epidemiology of group B Streptococcus: longitudinal observations during pregnancy. J Infect Dis. 1978 May;137(5):524–530. doi: 10.1093/infdis/137.5.524. [DOI] [PubMed] [Google Scholar]
  2. Onderdonk A. B., Delaney M. L., Hinkson P. L., DuBois A. M. Quantitative and qualitative effects of douche preparations on vaginal microflora. Obstet Gynecol. 1992 Sep;80(3 Pt 1):333–338. [PubMed] [Google Scholar]
  3. Onderdonk A. B., Polk B. F., Moon N. E., Goren B., Bartlett J. G. Methods for quantitative vaginal flora studies. Am J Obstet Gynecol. 1977 Aug 1;128(7):777–781. doi: 10.1016/0002-9378(77)90720-7. [DOI] [PubMed] [Google Scholar]
  4. Onderdonk A. B., Zamarchi G. R., Rodriguez M. L., Hirsch M. L., Muñoz A., Kass E. H. Qualitative assessment of vaginal microflora during use of tampons of various compositions. Appl Environ Microbiol. 1987 Dec;53(12):2779–2784. doi: 10.1128/aem.53.12.2779-2784.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Onderdonk A. B., Zamarchi G. R., Rodriguez M. L., Hirsch M. L., Muñoz A., Kass E. H. Quantitative assessment of vaginal microflora during use of tampons of various compositions. Appl Environ Microbiol. 1987 Dec;53(12):2774–2778. doi: 10.1128/aem.53.12.2774-2778.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Ross R. A., Lee M. L., Delaney M. L., Onderdonk A. B. Mixed-effect models for predicting microbial interactions in the vaginal ecosystem. J Clin Microbiol. 1994 Apr;32(4):871–875. doi: 10.1128/jcm.32.4.871-875.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Schuchat A., Wenger J. D. Epidemiology of group B streptococcal disease. Risk factors, prevention strategies, and vaccine development. Epidemiol Rev. 1994;16(2):374–402. doi: 10.1093/oxfordjournals.epirev.a036159. [DOI] [PubMed] [Google Scholar]

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