title: Implications of screening and childcare exclusion policies for children with Shiga-toxin producing Escherichia coli infections: lessons learned from an outbreak in a daycare centre, Norway, 2012.
abstract: BACKGROUND
  In Norway, it is recommended that children with Shiga-Toxin producing Escherichia coli (STEC) infections are excluded from daycare centers until up to five consecutive negative stool cultures are obtained. Children with gastrointestinal illness of unknown etiology are asked to remain home for 48 hours after symptoms subside. On 16 October 2012, two cases of STEC infection were reported from a daycare center, where other children were also symptomatic. Local health authorities temporarily closed the daycare center and all children and staff were screened for pathogenic E. coli. We present the results of the outbreak investigation in order to discuss the implications of screening and the exclusion policies for children attending daycare in Norway.
  
  
  METHODS
  Stool specimens for all children (n = 91) and employees at the daycare center (n = 40) were tested for pathogenic E. coli. Information on demographics, symptoms and potential exposures was collected from parents through trawling interviews and a web-based questionnaire. Cases were monitored to determine the duration of shedding and the resulting exclusion period from daycare.
  
  
  RESULTS
  We identified five children with stx1- and eae-positive STEC O103:H2 infections, and one staff member and one child with STEC O91:H- infections. Three additional children who tested positive for stx1 and eae genes were considered probable STEC cases. Three cases were asymptomatic. Median length of time of exclusion from daycare for STEC cases was 53 days (range 9 days-108 days). Survey responses for 75 children revealed mild gastrointestinal symptoms among both children with STEC infections and children with negative microbiological results. There was no evidence of common exposures; person-to-person transmission was likely.
  
  
  CONCLUSIONS
  The results of screening indicate that E. coli infections can spread in daycare centres, reflected in the proportion of children with STEC and EPEC infections. While screening can identify asymptomatic cases, the implications should be carefully considered as it can produce unanticipated results and have significant socioeconomic consequences. Daycare exclusion policies should be reviewed to address the management of prolonged asymptomatic shedders.
authors.affiliation: Department of Infectious Disease Epidemiology, Norwegian Institute of Public Health, P.O. Box 4404, Nydalen, NO-0403, Oslo, Norway. emily.macdonald@fhi.no.|European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control, Stockholm, Sweden. emily.macdonald@fhi.no.
authors.forename: Emily
authors.initials: E
authors.lastname: MacDonald
authors.affiliation: Municipality of Vennesla, Postboks 25, 4701, Vennesla, Norway. per.kjetil.dalane@vennesla.kommune.no.
authors.forename: Per Kjetil
authors.initials: PK
authors.lastname: Dalane
authors.affiliation: Epidemi, Lasarettet, Odderøya, 4610, Kristiansand, Norway. preben@epidemi.no.
authors.forename: Preben
authors.initials: P
authors.lastname: Aavitsland
authors.affiliation: Department of Foodborne Infections, Norwegian Institute of Public Health, P.O. Box 4404, Nydalen NO-0403, Oslo, Norway. LinThorstensen.Brandal@fhi.no.
authors.forename: Lin Thorstensen
authors.initials: LT
authors.lastname: Brandal
authors.affiliation: Department of Foodborne Infections, Norwegian Institute of Public Health, P.O. Box 4404, Nydalen NO-0403, Oslo, Norway. Astrid.Louise.Wester@fhi.no.
authors.forename: Astrid Louise
authors.initials: AL
authors.lastname: Wester
authors.affiliation: Department of Infectious Disease Epidemiology, Norwegian Institute of Public Health, P.O. Box 4404, Nydalen, NO-0403, Oslo, Norway. line.vold@fhi.no.
authors.forename: Line
authors.initials: L
authors.lastname: Vold
mesh_terms: D000328:Adult; D057138:Bacterial Shedding; D002656:Child Day Care Centers; D002675:Child, Preschool; D004196:Disease Outbreaks; D004927:Escherichia coli Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control; D029968:Escherichia coli Proteins / Q000235:genetics; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008403:Mass Screening; D009664:Norway / Q000453:epidemiology; D054323:Shiga-Toxigenic Escherichia coli / Q000235:genetics / Q000302:isolation & purification*; D018582:Sick Leave
chemical_list: D029968:Escherichia coli Proteins