title: Comparing listeriosis risks in at-risk populations using a user-friendly quantitative microbial risk assessment tool and epidemiological data.
abstract: Although infection by the pathogenic bacterium Listeria monocytogenes is relatively rare, consequences can be severe, with a high case-fatality rate in vulnerable populations. A quantitative, probabilistic risk assessment tool was developed to compare estimates of the number of invasive listeriosis cases in vulnerable Canadian subpopulations given consumption of contaminated ready-to-eat delicatessen meats and hot dogs, under various user-defined scenarios. The model incorporates variability and uncertainty through Monte Carlo simulation. Processes considered within the model include cross-contamination, growth, risk factor prevalence, subpopulation susceptibilities, and thermal inactivation. Hypothetical contamination events were simulated. Results demonstrated varying risk depending on the consumer risk factors and implicated product (turkey delicatessen meat without growth inhibitors ranked highest for this scenario). The majority (80%) of listeriosis cases were predicted in at-risk subpopulations comprising only 20% of the total Canadian population, with the greatest number of predicted cases in the subpopulation with dialysis and/or liver disease. This tool can be used to simulate conditions and outcomes under different scenarios, such as a contamination event and/or outbreak, to inform public health interventions.
authors.affiliation: Public Health Agency of Canada,Guelph,Ontario,Canada.
authors.forename: L E
authors.initials: LE
authors.lastname: Falk
authors.affiliation: Public Health Agency of Canada,Guelph,Ontario,Canada.
authors.forename: K A
authors.initials: KA
authors.lastname: Fader
authors.affiliation: Public Health Agency of Canada,Guelph,Ontario,Canada.
authors.forename: D S
authors.initials: DS
authors.lastname: Cui
authors.affiliation: Public Health Agency of Canada,Guelph,Ontario,Canada.
authors.forename: S C
authors.initials: SC
authors.lastname: Totton
authors.affiliation: Public Health Agency of Canada,Guelph,Ontario,Canada.
authors.forename: A M
authors.initials: AM
authors.lastname: Fazil
authors.affiliation: Public Health Agency of Canada,Guelph,Ontario,Canada.
authors.forename: A M
authors.initials: AM
authors.lastname: Lammerding
authors.affiliation: Public Health Agency of Canada,Guelph,Ontario,Canada.
authors.forename: B A
authors.initials: BA
authors.lastname: Smith
mesh_terms: D002170:Canada / Q000453:epidemiology; D005516:Food Microbiology / Q000379:methods*; D006801:Humans; D008089:Listeria monocytogenes / Q000302:isolation & purification*; D008088:Listeriosis / Q000453:epidemiology* / Q000382:microbiology; D008460:Meat / Q000382:microbiology*; D008461:Meat Products / Q000382:microbiology; D015233:Models, Statistical; D008962:Models, Theoretical; D018570:Risk Assessment; D035501:Uncertainty
keywords: At-risk populations; Listeria; food safety; risk factors; vulnerability