Officials with the Health Department of Northwest Michigan are warning residents of several norovirus outbreaks occurring in the area, and in conjunction are offering precautionary measures to keep summer dining experiences safe. Noroviruses are a group of viruses that cause gastroenteritis in people. The most common way to become infected with norovirus — also known as the "stomach flu" — is through contact with an infected person or by ingesting contaminated food or water. Norovirus illness usually begins 24-28 hours after exposure, but can appear as early as 10 hours after exposure. The illness is usually brief, with symptoms lasting only 1-2 days. Common symptoms include nausea, vomiting, diarrhea, stomach cramping, low-grade fever, chills, headache, muscle aches and a general sense of tiredness. It should be noted a norovirus infection is not related to influenza (flu), which is a respiratory viral illness that can cause fever, cough, chills, headache, muscle ac...