Tests Confirm Norovirus as Cause of Vegas Outbreak Health officials have confirmed norovirus is behind an outbreak at a youth football tournament in Las Vegas last week that sent more than two dozen people to the emergency room. Southern Nevada Health District spokeswoman Jennifer Sizemore said Monday that two stool samples tested positive for the virus, which is a mostly food- or water-borne illness that can also be spread by an infected person. Tournament spokesman Justin Gates said some 90 to 100 players, coaches and parents developed flu-like symptoms of nausea, vomiting and diarrhea during the four-day National Youth Football Championships that ended Saturday. Clark County firefighters responded to the Rio casino on Friday and 18 guests were taken to the hospital, although Gates says nobody stayed at the hospital for long. Check back soon for further information. AP's earlier story is below. As health officials investigate an outbreak at a youth football tournament that sent an estimated 28 people to the emergency room, organizers said it appears to be just a bad stomach bug that swept through groups of children in close quarters. The outbreak prompted tournament organizers to prohibit end-of-the-game handshakes between opposing players out of fear that participants might infect each other. Health officials are working from the assumption that it's norovirus, a mostly food- or water-borne illness that can also be spread by an infected person. There have been no obvious commonalities between the cases, such as a restaurant or hotel that all sick people visited. "It's just a run-of-the-mill old virus," Gates said. It's a weird year when you don't have this go through a team. Southern Nevada Health District officials issued surveys to attendees and are conducting tests on samples to make a more definitive ruling in coming weeks, spokeswoman Jennifer Sizemore said. The outbreak attracted attention when Clark County firefighters responded Friday to a cluster of sick people at the Rio casino, where the tournament was headquartered. Eighteen people, including five children, were taken from the hotel to hospitals. None of those taken to emergency rooms stayed for long, Gates said. Of the estimated 90 to 100 people who fell ill, a Santa Monica, Calif., team accounted for about 50 cases and a Bakersfield, Calif., team accounted for some 25 cases, Gates said. He suspects some people may have caught the sickness before coming to the tournament, and spread it to others during long bus rides. Nine of 100 teams from across the country were affected, Gates said, but it only stuck a little more than 1 percent of 7,000 attendees. One game had to be forfeited because of sick players. The tournament, organized by the Florida-based Sports Network International, draws teams from 17 states and as far as Panama. Players range in age from 6 to 15. Associated Press writer Martin Griffith contributed to this report from Reno.