One of six people suspected of contracting hepatitis E after eating pork intestines at a barbecue restaurant in Kitami, Hokkaido, has died, health ministry and Hokkaido government officials said Sunday.

The hepatitis E virus is easily destroyed by heat, and infection through food can be prevented if meat is cooked at a sufficiently high temperature.

Patrons at the restaurant grill their own meat and officials suspect the intestines were not sufficiently cooked. Hokkaido government officials are investigating how the six contracted the virus.