Pérez-Rodríguez F, van Asselt E D, Garcia-Gimeno R M, Zurera G, Zwietering M H
Department of Food Science and Technology, University of Córdoba, Campus de Rabanales, C-1, 14014 Córdoba, Spain.
J Food Prot. 2007 May;70(5):1137-52. doi: 10.4315/0362-028x-70.5.1137.
The risk assessment study of Listeria monocytogenes in ready-to-eat foods conducted by the U.S. Food and Drug Administration is an example of an extensive quantitative microbiological risk assessment that could be used by risk analysts and other scientists to obtain information and by managers and stakeholders to make decisions on food safety management. The present study was conducted to investigate how detailed sensitivity analysis can be used by assessors to extract more information on risk factors and how results can be communicated to managers and stakeholders in an understandable way. The extended sensitivity analysis revealed that the extremes at the right side of the dose distribution (at consumption, 9 to 11.5 log CFU per serving) were responsible for most of the cases of listeriosis simulated. For concentration at retail, values below the detection limit of 0.04 CFU/g and the often used limit for L. monocytogenes of 100 CFU/g (also at retail) were associated with a high number of annual cases of listeriosis (about 29 and 82%, respectively). This association can be explained by growth of L. monocytogenes at both average and extreme values of temperature and time, indicating that a wide distribution can lead to high risk levels. Another finding is the importance of the maximal population density (i.e., the maximum concentration of L. monocytogenes assumed at a certain temperature) for accurately estimating the risk of infection by opportunistic pathogens such as L. monocytogenes. According to the obtained results, mainly concentrations corresponding to the highest maximal population densities caused risk in the simulation. However, sensitivity analysis applied to the uncertainty parameters revealed that prevalence at retail was the most important source of uncertainty in the model.
美国食品药品监督管理局开展的即食食品中单核细胞增生李斯特菌风险评估研究，是一项广泛的定量微生物风险评估实例，风险分析师和其他科学家可借此获取信息，管理者和利益相关方则可据此做出食品安全管理决策。本研究旨在调查评估人员如何运用详细的敏感性分析来获取更多关于风险因素的信息，以及如何以易懂的方式将结果传达给管理者和利益相关方。扩展的敏感性分析表明，剂量分布右侧的极端情况（食用时每份9至11.5 log CFU）导致了模拟的大多数李斯特菌病病例。对于零售时的浓度，低于0.04 CFU/g的检测限以及常用的单核细胞增生李斯特菌限值100 CFU/g（同样在零售时）与每年大量的李斯特菌病病例相关（分别约为29%和82%）。这种关联可以通过单核细胞增生李斯特菌在平均温度和极端温度及时间下的生长来解释，这表明广泛的分布会导致高风险水平。另一个发现是最大种群密度（即在特定温度下假设的单核细胞增生李斯特菌的最大浓度）对于准确估计诸如单核细胞增生李斯特菌等机会性病原体感染风险的重要性。根据所得结果，在模拟中主要是对应最高最大种群密度的浓度导致了风险。然而，应用于不确定性参数的敏感性分析表明，零售时的患病率是模型中不确定性的最重要来源。
