Health officials are investigating an outbreak that sickened dozens of people at the Verizon Wireless Center in Mankato last week. A Minnesota Department of Health spokesperson says the outbreak appears to be norovirus. The virus is spread through contact with fecal matter, but it’s still too soon to determine if it was spread through food at the civic center. More than 50 people were sickened after the Greater Mankato Growth event a week ago, attended by more than 460 people. The health department also has received reports of people who contracted the illness after attending the Veterans Stand Down event at the civic center last Wednesday. Norovirus causes vomiting, nausea or diarrhea. The virus is usually not considered serious and most people recover in one or two days.