College and universities across the state – and across the country – are attributing coronavirus outbreaks on campuses to off-campus social events.

Michigan State University, Notre Dame and the University of North Carolina all walked back or delayed reopening plans after infection rates increased.

School officials at Illinois Wesleyan University in Normal announced 9 cases of the virus were linked to off-campus parties where the school said consistent use of face masks and social distancing did not occur.

Illinois State University spokesman Eric Jome said it is difficult to police off-campus events.

“For simply attending parties, we can’t hand out any sort of punishment or any sort of discipline for that, but really encouraging and urging people to avoid these large gatherings,” Jome said.

Illinois State, which received just over $16 million from the Higher Education Emergency Relief Fund, decided to go mostly online to begin the fall semester.

A dozen Bradley University students recently tested positive for COVID-19. School officials determined the outbreak stemmed from an off-campus gathering in which attendees didn’t wear masks or practice social distancing.

The mayors of both Champaign and Urbana, the home of the University of Illinois, have issued orders requiring bar and restaurant patrons to to stay seated most of the time. In Champaign, Mayor Deb Feinen issued an order limiting customer seating at Campustown restaurants and bars to outdoors areas only now through Labor Day. Emergency orders from the two mayors also set crowd limits and require face masks and social distancing at private parties on and near the U of I campus.

At Northern Illinois University in DeKalb, the virus has not been much of a problem.

Less than a week after students moved back to campus to begin the fall semester, only two cases of the COVID-19 were reported. The cases were identified Aug. 21, an employee and one student, according to NIU’s campus dashboard.