Quantitative Microbial Risk Assessment Model to Estimate Exposure to Campylobacter from Consumption of Chicken in the United States

Abstract

Public health costs of foodborne campylobacteriosis are estimated to cost more than a billion dollars in the United States annually. This pathogen has been primarily associated with chicken production and processing which is a ~$33 billion industry. To further identify practices that could reduce Campylobacter presence, concentration, and persistence in chicken prior to consumption a quantitative microbial risk assessment (QMRA) was conducted for boneless, skinless chicken breast meals prepared and consumed domestically in the contiguous United States. This QMRA model was developed with @RISK software (Palisade Corp., Ithaca, NY) and data inputs can be easily modified and updated. QMRA is a powerful analytic method that can be utilized to model the dynamics between the food pathogen, food commodity, and ingestion. It provides insight into the impacts of the process in its interaction and its surrounding environment. The baseline model determined that consumption of this product resulted in annual means of infections: 328,257, illnesses: 108,174, hospitalizations: 27,754, deaths: 37, cases of Campylobacter-associated Guillain-Barré Syndrome (GBS): 1,373, and cases of Campylobacter-associated Irritable Bowel Syndrome (IBS): 9,501. The associated annual economic burdens were ~$192 million for acute campylobacteriosis, ~$77 million for GBS, and ~$96 million for IBS. The effects of targeting and modifying the baseline model's inputs within the farm-to-fork process were studied as follows: Post grow-out (1) prevalence and (2) concentration of Campylobacter on chickens at the farm prior to transport, (3) transport crate cleaning frequency prior to loading, (4) temperature storage conditions at post processing/ pre-retail, (5) the frequency of handwashing in the preparation and handling of a chicken meal, and (6) the combination Campylobacter mitigation models using the inputs from (2) and (4). Mean yearly illnesses are estimated to decrease by approximately half if on-farm Campylobacter prevalence was lowered to 35-50% from the baseline level of 76%. An additional ~50,000 illnesses can be expected if the proportion of home preparers who do not wash their hands increases from 8.3% (baseline) to 20%. The combined effects of reducing on-farm Campylobacter concentrations and increasing the proportion of product frozen in-plant have greater impacts on reducing yearly campylobacteriosis and associated costs than either intervention alone.