When I think Minnesota, I think raw oysters.

No, I never think that about anywhere.

Jeremy Olson of the Star Tribune reports that city health inspectors in Minneapolis are investigating a summer increase in foodborne illnesses related to norovirus and Vibrio, a bacteria found in raw oysters.

The increases were highlighted in the city’s “food establishment” newsletter, released Thursday.

“The reason for the spike in norovirus outbreaks is not known,” the advisory stated. “The Vibrio outbreaks are due to higher concentrations of bacteria in some oyster beds during the summer.”

Cases of norovirus, a highly contagious bug that causes severe vomiting and diarrhea, are not required to be reported to the Minnesota Department of Health, but the state agency has received reports of a slight uptick that is unusual for this time of year.