Cases of norovirus, also known as the winter vomiting bug, are spreading in Wyoming according to the Wyoming Department of Public Health. Norovirus results in stomach aches, vomiting and watery diarrhea. The disease is infectious and can be spread through personal contact or though contaminated foods and surfaces. Symptoms of Norovirus generally last for two to three days with no lasting affects, but individuals with auto immune diseases should be especially cautious. At this time the cases are concentrated in the Cheyenne and Casper areas, but there is a chance that cases could spread to the rest of the state.