Laboratory of Veterinary Epidemiology (Epilab), Department of Preventive Veterinary Medicine, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
Technical University of Denmark - National Food Institute, Søborg, Denmark.
Risk Anal. 2017 Oct;37(10):1849-1864. doi: 10.1111/risa.12753. Epub 2016 Dec 20.
The objective of meat inspection is to promote animal and public health by preventing, detecting, and controlling hazards originating from animals. With the improvements of sanitary level in pig herds, the hazards profile has shifted and the inspection procedures no longer target major foodborne pathogens (i.e., not risk based). Additionally, carcass manipulations performed when searching for macroscopic lesions can lead to cross-contamination. We therefore developed a stochastic model to quantitatively describe cross-contamination when consecutive carcasses are submitted to classic inspection procedures. The microbial hazard used to illustrate the model was Salmonella, the data set was obtained from Brazilian slaughterhouses, and some simplifying assumptions were made. The model predicted that due to cross-contamination during inspection, the prevalence of contaminated carcass surfaces increased from 1.2% to 95.7%, whereas the mean contamination on contaminated surfaces decreased from 1 logCFU/cm² to -0.87 logCFU/cm², and the standard deviations decreased from 0.65 to 0.19. These results are explained by the fact that, due to carcass manipulations with hands, knives, and hooks, including the cutting of contaminated lymph nodes, Salmonella is transferred to previously uncontaminated carcasses, but in small quantities. These small quantities can easily go undetected during sampling. Sensitivity analyses gave insight into the model performance and showed that the touching and cutting of lymph nodes during inspection can be an important source of carcass contamination. The model can serve as a tool to support discussions on the modernization of pig carcass inspection.
肉品检验的目的是通过预防、检测和控制源自动物的危害，促进动物和公共卫生。随着猪群卫生水平的提高，危害特征已经发生转变，检验程序不再针对主要食源性致病菌（即非基于风险）。此外，在寻找宏观病变时进行的胴体操作可能导致交叉污染。因此，我们开发了一个随机模型来定量描述连续胴体在进行经典检验程序时的交叉污染情况。用于说明模型的微生物危害是沙门氏菌，数据集来自巴西屠宰场，并且做了一些简化假设。模型预测，由于检验过程中的交叉污染，受污染胴体表面的流行率从 1.2%增加到 95.7%，而污染表面的平均污染程度从 1 对数 CFU/cm²降低到-0.87 对数 CFU/cm²，标准差从 0.65 降低到 0.19。这些结果可以解释为，由于用手、刀和钩子进行胴体操作，包括切割污染的淋巴结，沙门氏菌会转移到之前未受污染的胴体上，但数量很少。这些少量的细菌在采样过程中很容易被忽视。敏感性分析深入了解了模型的性能，并表明在检验过程中触摸和切割淋巴结可能是胴体污染的一个重要来源。该模型可以作为支持讨论猪胴体检验现代化的工具。
