A school in Westford, Massachusetts, is undergoing extensive cleaning Thursday after four students were diagnosed with the staph infection MRSA.
School officials at Westford Academy say they don't know if the bacteria originated from one of Westford's students or another athlete who came in from another school.
All surfaces are being disinfected, starting with the locker rooms, gyms and wrestling mats. The school will be closed Thursday.
Health officials say they believe this is isolated to Westford Academy.
MRSA can be a difficult bacteria to treat because it is resistant to some antibiotics.
The infection is typically mild, but it can spread easily in crowded places.