The Erie County Health Department is investigating a possible measles exposure at Williamsville South High School.

Health officials say this is not a confirmed case.

The possible exposure may have happened on Friday.

A letter has been sent out to parents saying that while the risk of exposure is very low, “we are informing all students, parents, faculty and staff who may have been exposed because measles is easily passed from person to person.”

This alert comes less than a week after county health officials say nearly 200 students in the district may have been exposed to tuberculosis.