title: Evaluation of a rapid, real-time intrapartum group B streptococcus assay.
abstract: OBJECTIVE
  We sought to evaluate an intrapartum nucleic acid amplification test (NAAT) for group B streptococcus (GBS).
  
  
  METHODS
  This was a prospective cohort study of 559 women comparing intrapartum GBS culture with antepartum culture and intrapartum NAAT.
  
  
  RESULTS
  GBS prevalence was 19.5% by antepartum culture and 23.8% by intrapartum culture. Compared with intrapartum culture, antepartum culture had 69.2% sensitivity (60.6-76.9%) and 96.0% specificity (93.7-97.7%). The NAAT demonstrated sensitivity of 90.8% (84.6-95.2%), specificity of 97.6% (95.6-98.8%), and predictive values >92%. The incidence of discordant cultures was 10.4%. Of the women with negative antepartum and positive intrapartum cultures, only 1 (2.4%) received intrapartum antibiotics. Compared with white women, black (P = .02) and Hispanic (P = .02) women were more likely to have discordant cultures.
  
  
  CONCLUSIONS
  This intrapartum NAAT has excellent characteristics. It may be superior to antepartum culture for detecting intrapartum GBS-allowing more accurate management of laboring mothers and reducing neonatal GBS sepsis.
authors.affiliation: Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
authors.forename: Brett C
authors.initials: BC
authors.lastname: Young
authors.forename: Laura E
authors.initials: LE
authors.lastname: Dodge
authors.forename: Munish
authors.initials: M
authors.lastname: Gupta
authors.forename: Julie S
authors.initials: JS
authors.lastname: Rhee
authors.forename: Michele R
authors.initials: MR
authors.lastname: Hacker
mesh_terms: D000328:Adult; D001431:Bacteriological Techniques; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007743:Labor, Obstetric; D021141:Nucleic Acid Amplification Techniques; D011247:Pregnancy; D011446:Prospective Studies; D018805:Sepsis / Q000175:diagnosis* / Q000382:microbiology; D013290:Streptococcal Infections / Q000175:diagnosis*; D013292:Streptococcus agalactiae / Q000235:genetics / Q000302:isolation & purification*; D013997:Time Factors