LAS VEGAS -- Health officials have confirmed that norovirus is responsible for making dozens of players, coaches and parents sick at a youth football tournament in Las Vegas.
The Southern Nevada Health District confirmed that two people tested positive for the virus Monday.
Norovirus is a mostly spread by an infected person. According to the SNHD, there have been no link between the cases, such as a restaurant or hotel that all the people who became sick visited.
The outbreak was first reported Friday morning when the Clark County Fire Department responded to the Rio Hotel and Casino to take 18 people to the hospital.
Although the illness was first reported by people staying at the hotel, other area hotels have been asked to report similar illnesses to the health district.
A spokesman for the football tournament said some 90 to 100 players, coaches and parents reported symptoms of nausea, vomiting and diarrhea during the four-day National Youth Football Championships that ended Saturday.
Most cases of the illness resolve after a few days. The most serious complication can be dehydration.
The outbreak forced organizers to prohibit end-of-the-game handshakes between players for fear that more people would be infected.
Of the people who fell ill, a Santa Monica, Calif., team accounted for about 50 cases and a Bakersfield, Calif., team accounted for some 25 cases, tournament spokesman Justin 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.
(The Associated Press contributed to this report)