title: Sexual behavior and vaginal colonization by group B streptococcus among minority women.
abstract: OBJECTIVE
  To test the hypothesis that sexual behaviors predict colonization of the vagina by group B streptococcus among minority women.
  
  
  METHODS
  We conducted a prospective, descriptive study of 192 consecutive African-American (37%) and Hispanic women (63%). Each woman underwent a detailed interview concerning sexual behavior. Separate specimens were taken from the endocervix, upper vagina, lower vagina, and anorectum and placed in selective broth media for isolation of group B streptococcus. Significant behavioral predictors of vaginal group B streptococcus colonization and heavy (3-4+) colonization were identified using stepwise logistic regression.
  
  
  RESULTS
  The incidence of vaginal colonization was 39% and heavy colonization was 35%. Nineteen percent reported anal intercourse, 46% reported sex at least two times per week, and 21% reported more than one partner in the previous 30 days. The significant predictors of vaginal group B streptococcal infection were: African-American ethnicity, adjusted odds ratio (OR) 6.1 (95% confidence interval [CI] 2.5-15.1); presence of rectal group B streptococcus, adjusted OR 100.6 (95% CI 26.7-379.3); nulliparous, adjusted OR 3.6 (95% CI 1.4-9.5); and nonpregnant status, adjusted OR 3.9 (95% CI 1.3-12.2). The significant predictors of heavy colonization were: more than one partner in the last 30 days, adjusted OR 2.6 (95% CI 1.2-5.6); and African-American ethnicity, adjusted OR 2.3 (95% CI 1.2-4.5). Anal intercourse was associated with a reduced likelihood of vaginal group B streptococcal infection, adjusted OR 0.34 (95% CI 0.12-0.91).
  
  
  CONCLUSIONS
  Sexual behavior, especially anal intercourse, does not predict vaginal colonization by group B streptococcus. African-American women are more likely to have vaginal and heavy group B streptococcus colonization. Heavy vaginal colonization is associated with multiple partners in African-American women.
authors.affiliation: Department of Obstetrics and Gynecology, University of Texas Science Center at San Antonio, USA.
authors.forename: E R
authors.initials: ER
authors.lastname: Newton
authors.forename: M C
authors.initials: MC
authors.lastname: Butler
authors.forename: R N
authors.initials: RN
authors.lastname: Shain
mesh_terms: D000328:Adult; D001741:Black or African American; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D008913:Minority Groups; D016017:Odds Ratio; D011446:Prospective Studies; D012725:Sexual Behavior / Q000208:ethnology*; D013292:Streptococcus agalactiae / Q000254:growth & development*; D014621:Vagina / Q000382:microbiology*