title: Epidemiological analysis of a large enterohaemorrhagic Escherichia coli O111 outbreak in Japan associated with haemolytic uraemic syndrome and acute encephalopathy.
abstract: A large outbreak of enterohaemorrhagic Escherichia coli (EHEC) O111 and O157 occurred in Japan in April 2011. We conducted an unmatched case-control study and trace-back investigation to determine the source of EHEC O111 infection and risk factors for severe complications. Pulsed-field gel electrophoresis was performed to help define cases. A total of 86 individuals met the case definition. Of these, 40% experienced haemolytic uraemic syndrome (HUS), 24% acute encephalopathy, and 6% died. Illness was significantly associated with eating the raw beef dish yukhoe (odds ratio 19·64, 95% confidence interval 7·03-54·83), the likely food vehicle. EHEC O111 and its closely related stx-negative variants were found in the beef. HUS occurred most frequently in individuals aged 5-9 years, and this age group was significantly associated with acute encephalopathy. The prevalence of HUS and acute encephalopathy was higher than in previous non-O157-related outbreaks, indicating a high risk of severe complications.
authors.affiliation: National Institute of Infectious Diseases,Tokyo,Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Yahata
authors.affiliation: National Institute of Infectious Diseases,Tokyo,Japan.
authors.forename: T
authors.initials: T
authors.lastname: Misaki
authors.affiliation: Toyama City Hospital,Toyama,Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ishida
authors.affiliation: National Institute of Infectious Diseases,Tokyo,Japan.
authors.forename: M
authors.initials: M
authors.lastname: Nagira
authors.affiliation: Toyama Institute of Health,Toyama,Japan.
authors.forename: M
authors.initials: M
authors.lastname: Watahiki
authors.affiliation: Toyama Institute of Health,Toyama,Japan.
authors.forename: J
authors.initials: J
authors.lastname: Isobe
authors.affiliation: National Institute of Infectious Diseases,Tokyo,Japan.
authors.forename: J
authors.initials: J
authors.lastname: Terajima
authors.affiliation: National Institute of Infectious Diseases,Tokyo,Japan.
authors.forename: S
authors.initials: S
authors.lastname: Iyoda
authors.affiliation: National Institute of Infectious Diseases,Tokyo,Japan.
authors.forename: J
authors.initials: J
authors.lastname: Mitobe
authors.affiliation: National Institute of Infectious Diseases,Tokyo,Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ohnishi
authors.affiliation: Toyama Institute of Health,Toyama,Japan.
authors.forename: T
authors.initials: T
authors.lastname: Sata
authors.affiliation: National Institute of Infectious Diseases,Tokyo,Japan.
authors.forename: K
authors.initials: K
authors.lastname: Taniguchi
authors.affiliation: National Institute of Infectious Diseases,Tokyo,Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tada
authors.affiliation: National Institute of Infectious Diseases,Tokyo,Japan.
authors.forename: N
authors.initials: N
authors.lastname: Okabe
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D001927:Brain Diseases / Q000453:epidemiology* / Q000382:microbiology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D054324:Enterohemorrhagic Escherichia coli / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology*; D019453:Escherichia coli O157 / Q000302:isolation & purification; D005260:Female; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000453:epidemiology* / Q000382:microbiology*; D006463:Hemolytic-Uremic Syndrome / Q000453:epidemiology* / Q000382:microbiology*; D006801:Humans; D007223:Infant; D007564:Japan / Q000453:epidemiology; D008297:Male; D008460:Meat / Q000382:microbiology*; D008875:Middle Aged; D012307:Risk Factors
keywords: Escherichia coli infection; foodborne diseases; infectious disease outbreaks