The district health unit has determined suspected cases of food-borne illness were not acquired through a local sushi bard.

Last week the Thunder Bay District Health Unit announced they were investigating Bento Sushi, located inside the Real Canadian Superstore, after four people were reported to be ill after consuming the food on March 28.

Neither food or stool samples tested positive for foodborne illness but stool samples did test positive for norovirus.

While norovirus can be spread through food, the health unit determined the incubation period ruled out Bento Sushi as being the cause. Norovirus is most commonly spread through contaminated surfaces and then ingesting the virus.