title: Outbreak of shiga toxin-producing Escherichia coli serotype O26: H11 infection at a child care center in Colorado.
abstract: BACKGROUND
  Shiga toxin-producing Escherichia coli (STEC) O26:H11 is an emerging cause of disease with serious potential consequences in children. The epidemiology and clinical spectrum of O26:H11 are incompletely understood. We investigated an outbreak of O26:H11 infection among children younger than 48 months of age and employees at a child care center.
  
  
  METHODS
  Every employee at the center (n = 20) and every child <48 months (n = 55) were tested for STEC and administered a questionnaire. Thirty environmental health inspections and site visits were conducted. A cohorting strategy for disease control was implemented.
  
  
  RESULTS
  Eighteen confirmed and 27 suspect cases were detected. There were no hospitalizations. The illness rate was 60% for children and employees. The risk of being a case in children <36 months was twice the risk among children of 36 to 47 months (risk ratio: 2.10; 95% confidence interval: 1.00, 4.42). The median duration of shedding among symptomatic confirmed cases was 30.5 days (range: 14-52 days). Four (22%) confirmed cases were asymptomatic and 3 (17%) shed intermittently. Nearly half (49%) of the household contacts of confirmed cases developed a diarrheal illness. The outbreak was propagated by person-to-person transmission; cohorting was an effective disease control strategy.
  
  
  CONCLUSIONS
  This was the largest reported outbreak of O26:H11 infection in the United States and the largest reported non-O157 STEC outbreak in a US child care center. Non-O157 STEC infection is a differential diagnosis for outbreaks of diarrhea in child care settings. Aggressive disease control measures were effective but should be evaluated for outbreaks in other settings.
authors.affiliation: Tri-County Health Department, Greenwood Village, CO 80111, USA. jbrown@tchd.org
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Brown
authors.forename: Donna S
authors.initials: DS
authors.lastname: Hite
authors.forename: Laura A
authors.initials: LA
authors.lastname: Gillim-Ross
authors.forename: Hugh F
authors.initials: HF
authors.lastname: Maguire
authors.forename: Janine K
authors.initials: JK
authors.lastname: Bennett
authors.forename: Julia J
authors.initials: JJ
authors.lastname: Patterson
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Comstock
authors.forename: Anita K
authors.initials: AK
authors.lastname: Watkins
authors.forename: Tista S
authors.initials: TS
authors.lastname: Ghosh
authors.forename: Richard L
authors.initials: RL
authors.lastname: Vogt
mesh_terms: D000328:Adult; D002648:Child; D002656:Child Day Care Centers; D002675:Child, Preschool; D015331:Cohort Studies; D003120:Colorado / Q000453:epidemiology; D004196:Disease Outbreaks; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D054323:Shiga-Toxigenic Escherichia coli / Q000302:isolation & purification*; D011795:Surveys and Questionnaires