Last week more than 200 students at a Pennsylvania college were infected with norovirus, school officials confirmed.

Ursinus College said the Montgomery County Health Department confirmed Monday cases of norovirus, a contagious virus that causes gastroenteritis or inflammation of the stomach and intestines.

Classes resumed on Monday after being canceled Thursday afternoon and Friday. Events during the weekend were also canceled, reports Fox News.

According to officials, there was a significant decrease in the number of students reporting symptoms since the first reports came in Tuesday morning. While 22 students were treated at hospitals last week, none were admitted.

The school’s dining hall reopened after an inspection.

"Aggressive cleaning, sanitizing and disinfecting efforts will continue throughout the week with the help of additional custodial staff," the school said in a statement.

Ursinus spokeswoman Esme Artz said an internal count showed 214 students, faculty and staff having reported symptoms through Sunday evening, which totals almost 13 percent of the current enrollment of 1,650. She said additional reports continue to trickle in.

Officials continue to encourage anyone with symptoms to contact the school’s wellness center and said those who have been ill should take steps to stem the spread of the virus by practicing good hygiene, avoiding unaffected people for a few days and cleaning clothes, linens, and contaminated surfaces.