County public health officials confirmed that norovirus was responsible for causing hundreds of Kalmiopsis Elementary School students to become sick the past week.

Norovirus, a highly contagious virus, causes diarrhea, vomiting, nausea, stomach pains and fever and is not related to influenza. It is spread by coming into contact with infected individuals or food. People should wash their hands and avoid contact with those infected.

The virus is most contagious when people are still sick and three days after recovery from the virus. After recovering, people should stay home for another 48 hours to prevent spreading norovirus. Those infected with the virus should not share food or eating utensils.

Kalmiopsis Elementary School staff bleached and disinfected classrooms and offices Wednesday to eliminate the virus. About 95 students were absent Wednesday, down from a high of more than 200 last Friday.

Brody Hodges, environmental health coordinator for Curry Community Health, investigated the outbreak and said that norovirus is the most common food-borne illness in the United States.

"The best way to prevent it is to wash your hands," Hodges said. "Anything that could be infected should be cleaned with bleach."