Miami University of Ohio says some 200 students have been sickened in a norovirus outbreak.

It's the latest U.S. school to be hit by the highly contagious virus, which also affected some 100 students at the University of Michigan and 200 at Ursinus College in Pennsylvania in recent days.

School officials have urged students at Miami to step up hygiene efforts with frequent handwashing and disinfecting. Symptoms include vomiting, diarrhea and nausea.

The school also has expanded cleaning and availability of hand sanitizers.

University spokeswoman Carole Johnson says the norovirus was initially detected after five students became sick more than a week ago. She says the students afflicted earlier are doing much better now.

Most people recover in 24 to 72 hours.