Risk assessment of Listeria monocytogenes in poultry and beef

Purpose - A quantitative microbiological risk assessment (QMRA) was developed to estimate the probability of getting listeriosis as a consequence of chicken and beef consumption in Chile. The paper aims to discuss these issues. Design/methodology/approach - As a first step a deterministic retail-to-home model was constructed for the Chilean susceptible population, including storage, cross-contamination and cooking. Next, two probabilistic models were developed, including variability and/or the uncertainty of some of the parameters. The probabilistic models were analyzed by Monte Carlo simulations with 100,000 iterations. Findings - Of the total susceptible population used in the model (2.81 million people), the deterministic model estimated 11 and two listeriosis cases because of beef and poultry consumption, respectively and the variability model estimated a mean of 322 and 7,546 cases for beef and poultry consumption, respectively. The uncertainty analysis showed large ranges, with realistic estimates made with an initial concentration of Listeria monocytogenes of 0.04-1 CFU/g and a dose-response parameter r ranging from 10-14 to 10-10. Research limitations/implications - The lack of information was the major limitation of the model, so the generation of it has to be a priority in Chile for developing less uncertain risk assessments in the future. Practical implications - Raw animal products can be the cause of listeriosis cases if they are not stored, cooked and/or handled properly. Consumer education seems to be an essential factor for disease prevention. Originality/value - This is the first QMRA made in Chile, and also the first study of listeriosis in non-processed meat.