SCHOFIELD -- St. Peter Lutheran School will be closed today until Monday because more than one of every four students has been out sick.

Principal Scott Huebner said 22 of the school's 85 students were absent Tuesday and 18 were absent Monday.

"We've had a significant number of kids absent with flu-like symptoms. Today, we passed the 25 percent mark with absenteeism, and we don't see that getting better in the next few days," he said. "When you have that many kids absent, it does affect instruction."

Many of the students who were absent this week had symptoms consistent with the H1N1 virus, said Judy Burrows, program director for chronic disease prevention at the Marathon County Health Department. Symptoms of H1N1, or swine flu, include fever with a cough or sore throat. Health professionals in the area are doing limited testing for the virus, however.

"Most people that are presenting with influenza symptoms are testing positive for influenza A, and H1N1 is a form of influenza A," Burrows said. "This is clearly the predominant flu virus in the area. We know it's here and we know this is the strain that is circulating."

Closing the school should help diminish the prevalence of the virus in the students, Burrows said.

"We've learned with what happened in Medford. They closed for three days, and when they came back to school, absenteeism dropped dramatically," she said.

The school will be cleaned while students are away, with special concentration on common areas such as the lunch room and bathrooms, but no other extraordinary measures will be taken.

"The virus does die within eight to 12 hours, so we don't have to do any special cleaning," Huebner said. "The contact is what spreads things, especially with kids being with each other.

"Hopefully, being home, everybody can heal and recuperate and start fresh next week."