Unwell after Ueno Park Oyster Festival, confirmed to be norovirus meals poisoning | NHK

At an occasion held at Ueno Park in Taito Ward, Tokyo till the eighth of this month, quite a few folks complained of feeling unwell after consuming oyster dishes, and the Tokyo Metropolitan Government introduced on the sixteenth that the meals poisoning was brought on by norovirus. As meals poisoning brought on by norovirus usually happens in winter, the Tokyo Metropolitan Government is urging folks to watch out about washing their fingers and dealing with meals.

Source