title: Serotypes of group B streptococci in western Sweden and comparison with serotypes in two previous studies starting from 1988.
abstract: BACKGROUND
  Group B Streptococci (GBS) are the most common neonatal pathogens and infect immunocompromised and elderly individuals. The species has 10 different serotypes. Serotypes have been studied in the south-west area of Sweden in 1988-1997 and 1998-2001. The aim of this study was to study serotypes in the same area from 2004 to 2009.
  
  
  METHODS
  Invasive GBS isolates were collected prospectively from 2004 to 2009 in two counties in western Sweden with a population of 1.8 million, and were serotyped by latex agglutination. Clinical data were obtained from hospital records. During the study period 410 invasive GBS isolates from 398 patients were collected (multiple episodes ≥ 1 month apart). Clinical data were not available for two patients who are excluded. Four isolates were from stillborn neonates, 88 were from live born neonates and infants, and 318 from adults.
  
  
  RESULTS
  Serotype III was the most common serotype (48%) in neonates and infants followed by serotypes Ia (18%) and V (16%). In adults serotype V (39%) dominated followed by serotypes III (20%) and Ib (14%). There was a significant increase of serotype V in comparison with the first study (1988-1997) but there were no significant changes in the serotype distribution between the present study and the second study (1998-2001). There were a few cases of serotype VI-IX, both in children and adults, not seen in the previous studies. Serotype V was more common among patients with arthritis than with any other manifestation.
  
  
  CONCLUSIONS
  Changes in GBS serotypes occur over time in the same region, which must be considered when GBS vaccines are formulated.
authors.affiliation: Division of Neonatology, Department of Paediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden. margretkristin@gmail.com.|Department of Pediatrics, Neonatology, Sahlgrenska University Hospital, 41685, Gothenburg, Sweden. margretkristin@gmail.com.
authors.forename: Margrét Johansson
authors.initials: MJ
authors.lastname: Gudjónsdóttir
authors.affiliation: Division of Neonatology, Department of Paediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden. elisabet.hentz@vgregion.se.|Department of Pediatrics, Neonatology, Sahlgrenska University Hospital, 41685, Gothenburg, Sweden. elisabet.hentz@vgregion.se.
authors.forename: Elisabet
authors.initials: E
authors.lastname: Hentz
authors.affiliation: Department of Pediatrics, Queen Silvia Childrens' Hospital, Sahlgrenska University Hospital, Gothenburg, Sweden. stefan.berg@pediat.gu.se.
authors.forename: Stefan
authors.initials: S
authors.lastname: Berg
authors.affiliation: Department of Infectious Diseases, Skaraborg Hospital, Skövde, Sweden. erik.backhaus@vgregion.se.
authors.forename: Erik
authors.initials: E
authors.lastname: Backhaus
authors.affiliation: Division of Neonatology, Department of Paediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden. anders.elfvin@vgregion.se.|Department of Pediatrics, Neonatology, Sahlgrenska University Hospital, 41685, Gothenburg, Sweden. anders.elfvin@vgregion.se.
authors.forename: Anders
authors.initials: A
authors.lastname: Elfvin
authors.affiliation: Department of Bacteriology, Sahlgrenska University Hospital, Gothenburg, Sweden. samir.kawash@vgregion.se.
authors.forename: Samir
authors.initials: S
authors.lastname: Kawash
authors.affiliation: Department of Pediatrics, Queen Silvia Childrens' Hospital, Sahlgrenska University Hospital, Gothenburg, Sweden. birger.trollfors@vgregion.se.
authors.forename: Birger
authors.initials: B
authors.lastname: Trollfors
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006753:Hospital Records; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007841:Latex Fixation Tests; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D065288:Serogroup; D013290:Streptococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013292:Streptococcus agalactiae / Q000145:classification* / Q000302:isolation & purification; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult