title: Cohort study of a dual-pathogen point source outbreak associated with the consumption of chicken liver pâté, UK, October 2009.
abstract: BACKGROUND
  In October 2009, a dual-pathogen outbreak of Campylobacter and Salmonella occurred in which 59 cases were identified among guests attending a regional conference in the North of England. The mean symptomatic period was 5.4 days ( confidence intervals: 4.4-6.4), and over 84% of the cases had abdominal pain and diarrhoea.
  
  
  METHODS
  A retrospective cohort study was used to investigate the outbreak, and active case-finding was performed through the conference organizers and environmental health officers. A focused questionnaire was distributed to all guests via the event organizers 10 days after the conference.
  
  
  RESULTS
  Response rate among guests was 61% (107/175). A cohort study was undertaken, and a strong association was found between illness and consumption of chicken liver pâté, supporting the hypothesis that chicken liver pâté was the most likely cause of the outbreak.
  
  
  CONCLUSIONS
  This is the first mixed pathogen outbreak documented associated with the consumption of chicken liver pâté and adds to the evidence of potential hazards associated with the undercooking of poultry livers. A rapid outbreak investigation with collaboration between several organizations and the venue led to identification of the most probable source.
authors.affiliation: Yorkshire and the Humber Regional Epidemiology Unit, Health Protection Agency, Leeds, UK.
authors.forename: A
authors.initials: A
authors.lastname: Wensley
authors.forename: L
authors.initials: L
authors.lastname: Coole
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002169:Campylobacter Infections / Q000453:epidemiology* / Q000209:etiology; D060085:Coinfection / Q000453:epidemiology* / Q000209:etiology / Q000382:microbiology; D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D005260:Female; D005517:Foodborne Diseases / Q000453:epidemiology* / Q000209:etiology / Q000382:microbiology; D006801:Humans; D008099:Liver / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D011202:Poultry Products / Q000009:adverse effects* / Q000382:microbiology; D012189:Retrospective Studies; D012478:Salmonella Food Poisoning / Q000453:epidemiology* / Q000209:etiology; D011795:Surveys and Questionnaires; D006113:United Kingdom / Q000453:epidemiology
keywords: chicken liver; cohort; food poisoning; outbreak; pate