Survey of Norovirus in oysters collected from commercial harvesting farm in Fujian Province

Objective The contamination rate and gene groups of Norovirus(NoV) in oyster collected from harvesting farm in Fujian Province was investigated, and the contamination concentration was quantitatively analyzed, so as to provide data support for surveillance and risk assessment of Norovirus in food. Methods 244 oyster samples from oyster culture bed in Fujian Province were collected from August 2017 to September 2018. Norovirus nucleic acid was detected by realtime fluorescent quantitative polymerase chain reaction(PCR) to monitor Norovirus contamination in oyster production farm. Results The positive rate of Norovirus in 211 valid samples was 30.33%(64/211). Norovirus was detected in both GI and GII groups. 16.59%(35/211) of the samples were GI positive, 24.17%(51/211) of the samples were GII positive, and 10.43%(22/211) of the samples were both GI and GII positive. The range of the quantity of Norovirus in positive samples was from 1.05×102 -1.68×104 gene copies/g(digestive gland). Conclusion ected from commercial harvesting farm in Fujian Province were partly contaminated by Norovirus. A marked winter seasonality of contamination by both prevalence and quantity was observed. It is necessary to take more targeted risk management interventions in winter to reduce the risk of human illness resulting from Norovirus contamination of oysters.