RENO, Nevada — A Catholic high school in western Nevada has kept its campus closed this week after two students tested positive for COVID-19.

Bishop Manogue Catholic High School notified parents on Sunday that all students will now be distance learning, after some began attending in-person classes on alternate days, the Reno Gazette-Journal reported.

“It was a proactive measure and just to get on top of it,” school spokesperson Jill Johnson said, adding that there may be other students who are waiting for test results.

Johnson said about 50 students have been following isolation protocols because of possible exposure during off-campus activities, which may have included team practice and a social gathering.

The school reported its only other confirmed case of COVID-19 in August. Johnson said the school is now working with the health district to determine proper safety precautions.

Washoe County Health District Officer Kevin Dick said Wednesday that he was not aware of an outbreak at the school and that the district has not closed any schools because of COVID-19 cases.

The district websites stated Wednesday that there were two active COVID-19 cases at Sparks and Spanish Springs high schools, four cases at Mathews Elementary School and one active case at each North Valleys High School and Donner Springs Elementary.

The district does not report whether the cases are among students or staff.

The number of infections is thought to be far higher because many people have not been tested, and studies suggest people can be infected with the virus without feeling sick.

For most people, the new coronavirus causes mild or moderate symptoms, such as fever and cough that clear up in two to three weeks. For some — especially older adults and people with existing health problems — it can cause more severe illness, including pneumonia, and death.