title: Combining risk assessment and epidemiological risk factors to elucidate the sources of human E. coli O157 infection.
abstract: E. coli O157 can be transmitted to humans by three primary (foodborne, environmental, waterborne) and one secondary (person-to-person transmission) pathways. A regression model and quantitative microbiological risk assessments (QMRAs) were applied to determine the relative importance of the primary transmission pathways in NE Scotland. Both approaches indicated that waterborne infection was the least important but it was unclear whether food or the environment was the main source of infection. The QMRAs over-predicted the number of cases by a factor of 30 and this could be because all E. coli O157 strains may not be equally infective and/or the level of infectivity in the dose-response model was too high. The efficacy of potential risk mitigation strategies to reduce human exposure to E. coli O157 using QMRAs was simulated. Risk mitigation strategies focusing on food and environment are likely to have the biggest impact on infection figures.
authors.affiliation: Institute of Biological and Environmental Sciences, School of Biological Sciences, University of Aberdeen, UK.
authors.forename: O
authors.initials: O
authors.lastname: Rotariu
authors.forename: I D
authors.initials: ID
authors.lastname: Ogden
authors.forename: L
authors.initials: L
authors.lastname: MacRitchie
authors.forename: K J
authors.initials: KJ
authors.lastname: Forbes
authors.forename: A P
authors.initials: AP
authors.lastname: Williams
authors.forename: P
authors.initials: P
authors.lastname: Cross
authors.forename: C J
authors.initials: CJ
authors.lastname: Hunter
authors.forename: P F M
authors.initials: PF
authors.lastname: Teunis
authors.forename: N J C
authors.initials: NJ
authors.lastname: Strachan
mesh_terms: D000818:Animals; D002417:Cattle; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology*; D019453:Escherichia coli O157 / Q000302:isolation & purification*; D005243:Feces / Q000382:microbiology; D005516:Food Microbiology; D006801:Humans; D008460:Meat / Q000382:microbiology; D012307:Risk Factors; D012606:Scotland / Q000453:epidemiology; D012756:Sheep; D013997:Time Factors; D014871:Water Microbiology