Seven foodborne norovirus outbreaks attributable to the GII.P17-GII.17 strain were reported across Japan in 2017, causing illness in a total of 2,094 persons. Nori (dried shredded seaweed) was implicated in all outbreaks and tested positive for norovirus. Our data highlight the stability of norovirus in dehydrated food products.
Keywords: GII.P17-GII.17; Japan; dried shredded seaweed; food handler; food safety; foodborne disease; high infectivity; nori; norovirus; outbreaks; school lunch; viruses.