A quantitative microbial risk assessment model of Campylobacter in broiler chickens: Evaluating processing interventions

A probabilistic, evidence-based, quantitative microbial risk assessment model was developed to investigate public health risks associated with Campylobacter spp. contamination in broiler chicken supply systems in the United States, covering a farm-to-fork continuum. The objective of this study was to evaluate the effectiveness of intervention strategies in processing plants to protect the safety of chicken consumption and associated consumer health. A baseline model was constructed based on most common industrial practices with minimal interventions for model development and validation purposes. Sensitivity analysis was conducted to determine the most important input parameters for the model and identify critical control points along the supply chain. The effectiveness of possible intervention measures applicable during processing, including alternative processing strategies, chemical processing aids and physical methods to reduce risks of Campylobacter contamination in broiler chicken and campylobacteriosis among consumers were compared using scenario analysis. Input parameter distributions for the model were populated by the results of a previous systematic review and metaanalysis study, rather than evidence collected from the literature by convenience, to reduce possible bias in risk estimations. The final risk estimate was expressed as the number of campylobacteriosis cases per 100,000 persons per year and the intervention effectiveness was expressed as the relative change in campylobacteriosis risk if an intervention had been implemented compared with the baseline. The model estimated an occurrence of 274 (95% CI: 0-561) cases per 100,000 persons per year for baseline. Consumers' food safety practices and operations at processing plants are among the most significant factors to be targeted for reduction in consumers' exposure to Campylobacter through broiler consumption. Scenario analysis results indicate that chemical processing aids (individually or in tandem) can offer significant reduction in risk estimates. The model is expected to provide a framework for risk managers making risk-based decisions on changes in current poultry processing practices or implementation of alternative intervention strategies.