Technical Report: Review of Quantitative Risk Assessment of foodborne norovirus transmission

The specific questions to be addressed by the internal FSA review were:- Is the risk assessment approach taken appropriate to use the outputs for further analysis or decision-making? Are the food pathways that have been modelled appropriate for the UK and what is the impact of assumptions made, for example,in the immunity component and handling component of the model. - Are the parameters used in the risk assessment up to date, appropriate and adequately referenced? - Can any control measures be varied in the assessment and, if so, what is the impact of varying the control measured on the final output? A significant percentage of food consumed in the UK is prepared in advance of retail or available in catered establishments. Therefore, the QMRA included both domestic kitchen food pathways, catering establishments and take away foods. The UK is a net importer of certain food products and the percentage of imported versus domestically produced varies between seasons and between food product types. The prevalence of norovirus and level of contamination in both imported and domestically produced goods is poorly understood. As a key data gap, the NoVAS project was funded to experimentally test the prevalence of norovirus and level of contamination found at UK retail. Currently, there are insufficient data to stratify between domestically produced and imported products, or to assess the seasonal consumption of food products.