MOSES LAKE - Grant County Health District officials are urging residents to stay home if they get the stomach flu and frequently wash hands with soap and water. The warnings follow confirmation that an outbreak of stomach flu at Longview Elementary School was caused by a highly contagious virus.

The illness was diagnosed as norovirus, and closed Longview Elementary for the day on May 10. "The health district is getting reports of pockets of students in other Moses Lake schools with stomach illnesses," said Theresa Adkinson, the district's public information officer. "This is not completely unexpected as norovirus is a highly contagious illness and other community members are ill with similar symptoms."

About one-quarter of Longview's students were absent May 13, Adkinson said, the first day the school reopened. "The elevated absentee rate was expected because parents were asked to keep their sick children home for at least 48 hours after their symptoms stopped. If students show any signs of stomach pains or nausea the parents are called immediately and asked to pick up their child."

Adkinson said symptoms of norovirus usually include stomach aches, nausea, vomiting and diarrhea. Symptoms appear about 24 to 48 hours after exposure. The illness usually lasts one to three days, Adkinson said.

Preventing the virus from spreading involves a lot of soap and warm water. People should wash hands after using the bathroom, before eating or handling food. It has to be warm water and soap, because hand sanitizers don't kill the norovirus, Adkinson said.

People who are sick shouldn't prepare or handle food.

Any surfaces that have been touched by a sick person should be disinfected, first with soap and warm water and then with a solution of 10 percent bleach, one and one-half cups of bleach to one gallon of water, Adkinson said.

People who got sick should stay home for about 48 hours after they start feeling better, she said.