title: Incidence and severity of invasive Streptococcus pneumoniae, group A Streptococcus, and group B Streptococcus infections among pregnant and postpartum women.
abstract: BACKGROUND
  The epidemiology of streptococcal infection in pregnant and postpartum women is poorly described in recent literature. We used data from multistate surveillance for invasive Streptococcus pneumoniae, group A Streptococcus (GAS), and group B Streptococcus (GBS) infections to estimate disease incidence and severity in these populations.
  
  
  METHODS
  Cases were reported through the Centers for Disease Control and Prevention Active Bacterial Core surveillance, an active population- and laboratory-based system. A case was defined as illness in a woman aged 15-44 years with streptococcus isolated from a normally sterile body site during 2007-2009. Pregnant or postpartum status was recorded at the time of culture. Incidence was calculated as cases per 1000 woman-years with use of national Census data; 95% confidence intervals were calculated on the basis of λ distribution. We used multivariable logistic regression to explore associations between pregnant or postpartum status and hospital length of stay, a marker of disease severity.
  
  
  RESULTS
  We identified 1848 cases in women; 6.0% of women were pregnant, and 7.5% were postpartum. Pregnant women had a higher mean incidence of GBS disease, compared with nonpregnant women (0.04 cases per 1000 woman-years [range, 0.03-0.05 cases per 1000 woman-years] vs 0.02 cases per 1000 woman-years [range, 0.02-0.02 cases per 1000 woman-years]). Postpartum women had elevated mean incidence of all 3 pathogens, compared with nonpregnant women (S. pneumoniae: 0.15 cases per 1000 woman-years [range, 0.09-0.25 cases per 1000 woman-years] vs 0.052 cases per 1000 woman-years [range, 0.049-0.056 cases per 1000 woman-years]; GAS: 0.56 cases per 1000 woman-years [range, 0.42-0.70 cases per 1000 woman-years] vs 0.019 cases per 1000 woman-years [range, 0.017-0.021 cases per 1000 woman-years]; GBS: 0.49 cases per 1000 woman-years [range, 0.36-0.64 cases per 1000 woman-years] vs 0.018 [range, 0.016-0.020 cases per 1000 woman-years]). Neither pregnancy nor postpartum status was associated with longer length of stay among women infected with any of the 3 pathogens.
  
  
  CONCLUSIONS
  Although invasive streptococcal infections do not appear to be more severe in pregnant or postpartum women, postpartum women have a 20-fold increased incidence of GAS and GBS, compared with nonpregnant women.
authors.affiliation: Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Office of Workforce and Career Development, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
authors.forename: Meredith
authors.initials: M
authors.lastname: Deutscher
authors.forename: Melissa
authors.initials: M
authors.lastname: Lewis
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Zell
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Taylor
authors.forename: Chris
authors.initials: C
authors.lastname: Van Beneden
authors.forename: Stephanie
authors.initials: S
authors.lastname: Schrag
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D015994:Incidence; D007902:Length of Stay; D049590:Postpartum Period; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology* / Q000382:microbiology* / Q000473:pathology; D012307:Risk Factors; D012720:Severity of Illness Index; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology* / Q000473:pathology; D013292:Streptococcus agalactiae / Q000302:isolation & purification*; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*; D013297:Streptococcus pyogenes / Q000302:isolation & purification*; D055815:Young Adult