Modeling Preharvest and Harvest Interventions for Escherichia coli O157 Contamination of Beef Cattle Carcasses

Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506-5006, USA.
Journal of food protection (Impact Factor: 1.85). 09/2011; 74(9):1422-33. DOI: 10.4315/0362-028X.JFP-10-516
Source: PubMed


Field studies evaluating the effects of multiple concurrent preharvest interventions for Escherichia coli O157 are logistically and economically challenging; however, modeling techniques may provide useful information on these effects while also identifying crucial information
gaps that can guide future research. We constructed a risk assessment model with data obtained from a systematic search of scientific literature. Parameter distributions were incorporated into a stochastic Monte Carlo modeling framework to examine the impacts of different combinations of preharvest
and harvest interventions for E. coli O157 on the risk of beef carcass contamination. We estimated the risk of E. coli O157 carcass contamination conditional on preharvest fecal prevalence estimates, inclusion of feed additive(s) in the diet, vaccination for E. coli O157,
transport and lairage effects, hide intervention(s), and carcass intervention(s). Prevalence parameters for E. coli O157 were assumed to encompass potential effects of concentration; therefore, concentration effects were not specifically evaluated in this study. Sensitivity analyses
revealed that fecal prevalence, fecal-to-hide transfer, hide-to-carcass transfer, and carcass intervention efficacy significantly affected the risk of carcass contamination (correlation coefficients of 0.37, 0.56, 0.58, and −0.29, respectively). The results indicated that combinations
of preharvest interventions may be particularly important for supplementing harvest interventions during periods of higher variability in fecal shedding prevalence (i.e., summer). Further assessments of the relationships among fecal prevalence and concentration, hide contamination, and subsequent
carcass contamination are needed to further define risks and intervention impacts for E. coli O157 contamination of beef.

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    • "oneragan and Brashears , 2005 ) . Although interventions to reduce carcass contamination during processing are crit - ical to reducing human exposure to E . coli O157 , pre - har - vest interventions to reduce faecal prevalence and faecal to hide transfer were also important when multiple interven - tions were assessed in a risk assessment model ( Dodd et al . , 2011 ) . Risk assessment and prediction models suggest that a reduction in cattle shedding of E . coli O157 during the pre - harvest stage will reduce the burden of human E . coli O157 illnesses ( Rotariu et al . , 2012 ; Matthews et al . , 2013 ; Smith et al . , 2013 ) . Direct - fed microbials are defined by the US Food and Drug administra"
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