The Minnesota Department of Health has been investigating the outbreak of norovirus at downtown Duluth’s Tycoons Alehouse & Eatery that has been traced to uncooked vegetables served at three holiday parties on December 5.

About 30 people reported becoming ill from the outbreak.

The restaurant was never closed and management has since redoubled training and kitchen signage to remind staff to wash their hands before handling any food.

According to the state Health Department, noroviruses are members of a group of viruses called caliciviruses, formerly called “Norwalk-like viruses.” Norovirus infection causes gastroenteritis, which is an inflammation of the stomach and the small and large intestines.

Common symptoms include nausea, vomiting, diarrhea, abdominal cramps, headache, fever/chills and muscle aches. Symptoms usually begin 24 to 48 hours after infection, but can appear as early as 12 hours after exposure.