A ONE YEAR SURVEY OF NOROVIRUS IN UK OYSTERS COLLECTED AT THE POINT OF SALE

Contamination of bivalve shellfish, particularly oysters, with norovirus is recognised as a food safety risk and a potential contributor to the overall burden of gastroenteritis in the community. The United Kingdom (UK) has... [ view full abstract ]

Contamination of bivalve shellfish, particularly oysters, with norovirus is recognised as a food safety risk and a potential contributor to the overall burden of gastroenteritis in the community. The United Kingdom (UK) has comprehensive national baseline data on the prevalence, levels and seasonality of norovirus in oysters in production areas resulting from a previous two-year study (2009-2011). However, previously, data on final product as sold to the consumer has been lacking. As part of a wider project to establish the overall burden of foodborne norovirus in the UK this study (funded by the UK Food Standards Agency), aimed to address this data gap. 

A one year survey of oysters collected from the point-of-sale to the consumer was carried out from March 2015 – March 2016. A total of 630 samples were collected from 21 regions across the UK using a randomised sampling plan, and tested for norovirus using a method compliant with ISO 15216.

As in the previous study, norovirus RNA was detected in a high proportion of samples (68.7%), with a strong winter seasonality noted. However, levels detected in positive samples were considerably lower than seen previously. This presentation will summarise the findings of the survey and examine the possible causes of the lower levels observed, illuminating some of the difficulties of comparing data collected in different years.