title: Evaluation of universal antenatal screening for group B streptococcus.
abstract: BACKGROUND
  Group B streptococcal disease is one of the most common infections in the first week after birth. In 2002, national guidelines recommended universal late antenatal screening of pregnant women for colonization with group B streptococcus to identify candidates for intrapartum chemoprophylaxis.
  
  
  METHODS
  We evaluated the implementation of the guidelines in a multistate, retrospective cohort selected from the Active Bacterial Core surveillance, a 10-state, population-based system that monitors invasive group B streptococcal disease. We abstracted data from the labor and delivery records of a stratified random sample of live births and of all cases in which the newborn had early-onset group B streptococcal disease (i.e., disease in infants <7 days of age) in 2003 and 2004. We compared our results with those from a study with a similar design that evaluated screening practices in 1998 and 1999.
  
  
  RESULTS
  We abstracted records of 254 births in which the infant had group B streptococcal disease and 7437 births in which the infant did not. The rate of screening for group B streptococcus before delivery increased from 48.1% in 1998-1999 to 85.0% in 2003-2004; the percentage of infants exposed to intrapartum antibiotics increased from 26.8% to 31.7%. Chemoprophylaxis was administered in 87.0% of the women who were positive for group B streptococcus and who delivered at term, but in only 63.4% of women with unknown colonization status who delivered preterm. The overall incidence of early-onset group B streptococcal disease was 0.32 cases per 1000 live births. Preterm infants had a higher incidence of early-onset group B streptococcal disease than did term infants (0.73 vs. 0.26 cases per 1000 live births); however, 74.4% of the cases of group B streptococcal disease (189 of 254) occurred in term infants. Missed screening among mothers who delivered at term accounted for 34 of the 254 cases of group B streptococcal disease (13.4%). A total of 61.4% of the term infants with group B streptococcal disease were born to women who had tested negative for group B streptococcus before delivery.
  
  
  CONCLUSIONS
  Recommendations for universal screening were rapidly adopted. Improved management of preterm deliveries and improved collection, processing, and reporting of culture results may prevent additional cases of early-onset group B streptococcal disease.
authors.affiliation: Epidemic Intelligence Service Program, Office of Workforce and Career Development, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
authors.forename: Melissa K
authors.initials: MK
authors.lastname: Van Dyke
authors.forename: Christina R
authors.initials: CR
authors.lastname: Phares
authors.forename: Ruth
authors.initials: R
authors.lastname: Lynfield
authors.forename: Ann R
authors.initials: AR
authors.lastname: Thomas
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Arnold
authors.forename: Allen S
authors.initials: AS
authors.lastname: Craig
authors.forename: Janet
authors.initials: J
authors.lastname: Mohle-Boetani
authors.forename: Ken
authors.initials: K
authors.lastname: Gershman
authors.forename: William
authors.initials: W
authors.lastname: Schaffner
authors.forename: Susan
authors.initials: S
authors.lastname: Petit
authors.forename: Shelley M
authors.initials: SM
authors.lastname: Zansky
authors.forename: Craig A
authors.initials: CA
authors.lastname: Morin
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Spina
authors.forename: Kathryn
authors.initials: K
authors.lastname: Wymore
authors.forename: Lee H
authors.initials: LH
authors.lastname: Harrison
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Shutt
authors.forename: Joseph
authors.initials: J
authors.lastname: Bareta
authors.forename: Sandra N
authors.initials: SN
authors.lastname: Bulens
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Zell
authors.forename: Anne
authors.initials: A
authors.lastname: Schuchat
authors.forename: Stephanie J
authors.initials: SJ
authors.lastname: Schrag
mesh_terms: D019072:Antibiotic Prophylaxis / Q000706:statistics & numerical data*; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D019983:Guideline Adherence; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D016015:Logistic Models; D008403:Mass Screening; D011159:Population Surveillance; D017410:Practice Guidelines as Topic; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis*; D047928:Premature Birth / Q000382:microbiology; D011296:Prenatal Diagnosis; D012189:Retrospective Studies; D013290:Streptococcal Infections / Q000175:diagnosis* / Q000517:prevention & control / Q000635:transmission; D013292:Streptococcus agalactiae