Chicago School Shutters After 800 Kids, 50 Staff Ill With Suspected Norovirus

The St. Charles East High School in Chicago shut down for a second day Wednesday

"While a clinical determination has yet to be made about the stomach virus that is going around, the symptoms are similar to norovirus, so, we are following the procedures regarding norovirus," St. Charles District 303 said in a statement. "We are now working to assist the Illinois Department of Public Health in their efforts to more clearly identify this virus."

The virus sickens some 19 to 21 million Americans annually and contributes to as many as 800 deaths.

Classes at the school are set to resume on Thursday.

Symptoms of a widespread illness started appearing on Saturday night, ABC affiliate WLS-TV reported, when a boys' basketball game was postponed because 10 of the team's 14 players were ill.