title: Enhanced surveillance on food-borne disease outbreaks: dynamics of cross-contamination in biocidal wash procedure.
abstract: Understanding the geographic and temporal spread of food-borne diseases associated with fresh produce is crucial for informing adequate surveillance and control. As a first step towards this goal, we develop and analyze a novel three stage model at the processing/sanitization juncture in the fresh produce supply chain. The key feature of our model is its ability to describe the dynamics of cross-contamination during commercial wash procedures. In general, we quantify the degree of cross-contamination in terms of model parameters. Applying these results in the case of Escherichia coli O157:H7 contamination of fresh-cut romaine lettuce, we identify the mean wash time and free chlorine concentration as critical parameters. In addition to showing how these parameters affect contamination levels, we recommend that in order to prevent potential source misidentification, at least 2.2 mg/L of free chlorine should be used during a wash lasting at least 30s.
authors.affiliation: Centre for Disease Modelling, Department of Mathematics and Statistics, York University, Toronto, Canada. munther@mathstat.yorku.ca
authors.forename: Daniel
authors.initials: D
authors.lastname: Munther
authors.forename: Jianhong
authors.initials: J
authors.lastname: Wu
mesh_terms: D000465:Algorithms; D002713:Chlorine / Q000378:metabolism; D003257:Consumer Product Safety; D004196:Disease Outbreaks; D004202:Disinfectants / Q000494:pharmacology*; D019453:Escherichia coli O157; D005506:Food Contamination / Q000517:prevention & control*; D005511:Food Handling / Q000379:methods; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D008962:Models, Theoretical; D015203:Reproducibility of Results
chemical_list: D004202:Disinfectants; D002713:Chlorine