title: Community outbreak of perianal group A streptococcal infection in Denmark.
abstract: BACKGROUND
  Perianal group A streptococcal infection (PASI) occurs primarily in children. There is limited information on the incidence, transmission and treatment of PASI. We report a cluster of cases connected to a Danish kindergarten and observations of the incidence of PASI in the local population.
  
  
  METHODS
  A Danish rural community with 1765 children 15 years and younger registered with two general practice clinics.
  
  
  METHODS
  After being alerted of a possible cluster of PASI cases, all isolates of group A beta-hemolytic streptococci were collected and subjected to T typing and pulsed field gel electrophoresis (PFGE) if grown from either a rectal swab or an accompanying throat swab obtained in the offices of local general practitioners during the ensuing 4-month period. Clinical data were obtained from the files of the local general practitioners.
  
  
  RESULTS
  Twelve cases of PASI were caused by group A beta-hemolytic streptococci T type 28 with an identical PFGE profile: 6 of the cases were in children attending the same kindergarten, 4 were connected otherwise to the cluster and 2 cases seemed to be unrelated. Five cases of PASI with different T types and PFGE profiles were diagnosed during the same period giving an estimated annual incidence of 2 to 7 per 1000 children. Penicillin V was ineffective in 3 cases, and no recurrence was seen after change of the treatment to oral clarithromycin.
  
  
  CONCLUSIONS
  A clone of T type 28 seemed to be the cause of the largest cluster of PASI cases described thus far. Clarithromycin was effective as second line treatment. An estimated annual baseline incidence of 2 to 7 per 1000 in the local population indicates that PASI may not be as rare as previously estimated.
authors.affiliation: Department of Pediatrics, Aarhus University Hospital, Denmark. jesperpadkaer@yahoo.com
authors.forename: Jesper P
authors.initials: JP
authors.lastname: Petersen
authors.forename: Margit S
authors.initials: MS
authors.lastname: Kaltoft
authors.forename: Jens C
authors.initials: JC
authors.lastname: Misfeldt
authors.forename: Helga
authors.initials: H
authors.lastname: Schumacher
authors.forename: Henrik C
authors.initials: HC
authors.lastname: Schønheyder
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002648:Child; D002656:Child Day Care Centers; D002675:Child, Preschool; D016000:Cluster Analysis; D017714:Community-Acquired Infections / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D004269:DNA, Bacterial / Q000032:analysis; D003718:Denmark / Q000453:epidemiology; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D010502:Perineum / Q000382:microbiology; D012042:Registries; D012307:Risk Factors; D017678:Sex Distribution; D013290:Streptococcal Infections / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D013297:Streptococcus pyogenes / Q000302:isolation & purification*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial