Matsumoto University in Nagano announced on Tuesday that twenty students on the baseball team living in a dormitory complained of nausea. Seven of the students were diagnosed with the Norovirus. The university pointed to a meal served at the dormitory as the cause.
According to Nagano Prefecture, on the evening of the 15th, thirty-one students ate Saba-no Misoni (a cooked mackerel dish) and Rei Shabu Salad (cold pork salad) for dinner. Of the thirty-one students that ate the meal, twenty felt sick on the morning of the 16th. The Norovirus was also found in fecal matter taken from a cook at the dormitory.
Source: Sponichi 1/21/2014