title: Risk factors for Group B Streptococcus colonisation and disease in Gambian women and their infants.
abstract: OBJECTIVE
  To determine risk factors for GBS colonisation in Gambian mothers and in their infants from birth to day 60-89 of age.
  
  
  METHODS
  Swabs and breastmilk from mothers/infant pairs were collected and cultured on selective agar. Negative samples were analysed for GBS DNA via real-time PCR. Positive isolates were serotyped using multiplex PCR and gel-agarose electrophoresis.
  
  
  RESULTS
  Seven hundred and fifty women/infant pairs were recruited. 253 women (33.7%) were GBS-colonised at delivery. The predominant serotypes were: V (55%), II (16%), III (10%), Ia (8%) and Ib (8%). 186 infants were colonised (24.8%) at birth, 181 (24.1%) at 6 days and 96 at day 60-89 (14%). Infants born before 34 weeks of gestation and to women with rectovaginal and breastmilk colonisation at delivery had increased odds of GBS colonisation at birth. Season of birth was associated with increased odds of persistent infant GBS colonisation (dry season vs. wet season AOR 2.9; 95% CI 1.6-5.2).
  
  
  CONCLUSIONS
  GBS colonisation is common in Gambian women at delivery and in their infants to day 60-89 and is dominated by serotype V. In addition to maternal colonisation, breastmilk and season of birth are important risk factors for infant GBS colonisation.
authors.affiliation: Imperial College, Norfolk Place, London W2 1PG, UK; MRC Unit, Atlantic Road, Fajara, Gambia; Public Health England, Manor Farm Road, Porton Down SP4 0JG, UK; St George's University of London, Cranmer Terrace, London SW17 0RE, UK. Electronic address: K.mehring-le-doare@ic.ac.uk.
authors.forename: K
authors.initials: K
authors.lastname: Le Doare
authors.affiliation: MRC Unit, Atlantic Road, Fajara, Gambia. Electronic address: shjarju@mrc.gm.
authors.forename: S
authors.initials: S
authors.lastname: Jarju
authors.affiliation: MRC Unit, Atlantic Road, Fajara, Gambia. Electronic address: sdarboe@mrc.gm.
authors.forename: S
authors.initials: S
authors.lastname: Darboe
authors.affiliation: Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK. Electronic address: Fiona.warburton@phe.gov.uk.
authors.forename: F
authors.initials: F
authors.lastname: Warburton
authors.affiliation: Public Health England, Manor Farm Road, Porton Down SP4 0JG, UK. Electronic address: Andrew-gorringe@phe.gov.uk.
authors.forename: A
authors.initials: A
authors.lastname: Gorringe
authors.affiliation: St George's University of London, Cranmer Terrace, London SW17 0RE, UK. Electronic address: pheath@sgul.ac.uk.
authors.forename: P T
authors.initials: PT
authors.lastname: Heath
authors.affiliation: Imperial College, Norfolk Place, London W2 1PG, UK; MRC Unit, Atlantic Road, Fajara, Gambia. Electronic address: b.kampmann@ic.ac.uk.
authors.forename: B
authors.initials: B
authors.lastname: Kampmann
mesh_terms: D000293:Adolescent; D000328:Adult; D001431:Bacteriological Techniques; D005260:Female; D005714:Gambia / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D012703:Serotyping; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013292:Streptococcus agalactiae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D055815:Young Adult
keywords: Group B Streptococcus; Immunity; Neonatal infection; Vaccines