Iulietto Maria Francesca, Evers Eric G
EFSA J. 2020 Nov 26;18(Suppl 1):e181106. doi: 10.2903/j.efsa.2020.e181106. eCollection 2020 Nov.
In the kitchen of the consumer, two main transmission routes are relevant for quantitative microbiological risk assessment (QMRA): the route, where a pathogen on a food product may evade heating by transmission via hands, kitchen utensils and other surfaces, e.g. to non-contaminated products to be consumed raw; and the route, where pathogens remain on the food product and are for the most part inactivated through heating. This project was undertaken to model and estimate the magnitude of cross-contamination in the domestic environment. Scientific information from the relevant literature was collected and analyzed, to define the cross-contamination routes, to describe the variability sources and to extract and harmonise the transfer fractions to be included as model parameters. The model was used to estimate the relative impact of the cross-contamination routes for different scenarios. In addition, the effectiveness of several interventions in reducing the risk of food-borne diseases due to cross-contamination was investigated. The outputs of the model showed that the cutting board route presents a higher impact compared to other routes and replacement of the kitchen utensils is more effective than other interventions investigated; the transfer to other surfaces and objects, which can house bacteria in the environment, is also described. Laboratory cross-contamination trials have been performed to estimate bacterial transfer via cutting, from the external surface of the meat to the cutting surfaces and to the knife. The results, obtained from the laboratory trials, show magnitudes of and differences in the bacterial transfer fraction to the knife and the cutting surface in relation to which side of the meat is contaminated. Despite the complexity of factors which influence bacterial transfer, the combination of laboratory work with mathematical modelling enhanced scientific understanding and appreciation of the uncertainty of the estimates. QMRA methodology results in magnitude estimation of cross-contamination in the kitchen and evaluation of intervention strategies.
在消费者的厨房中，定量微生物风险评估（QMRA）涉及两条主要传播途径：一条途径是，食品上的病原体可能通过手、厨房用具和其他表面传播从而避开加热，例如传播到未受污染的即食产品上；另一条途径是，病原体残留在食品上，并在很大程度上通过加热而失活。开展该项目旨在对家庭环境中的交叉污染程度进行建模和估算。收集并分析了相关文献中的科学信息，以确定交叉污染途径、描述变异性来源，并提取和统一作为模型参数的转移系数。该模型用于估算不同场景下交叉污染途径的相对影响。此外，还研究了几种干预措施在降低交叉污染导致食源性疾病风险方面的有效性。模型输出结果表明，与其他途径相比，砧板途径的影响更大，更换厨房用具比所研究的其他干预措施更有效；还描述了病原体向环境中可能藏有细菌的其他表面和物体的转移情况。已进行实验室交叉污染试验，以估算通过切割从肉的外表面到切割表面以及到刀具的细菌转移情况。从实验室试验获得的结果表明，根据肉的哪一侧被污染，细菌转移到刀具和切割表面的转移系数大小及差异情况。尽管影响细菌转移的因素复杂，但将实验室工作与数学建模相结合，增强了对估计不确定性的科学理解和认识。QMRA方法可对厨房中的交叉污染程度进行估算，并对干预策略进行评估。
