Parents alerted of whooping cough in Elmbrook School Dist.

BROOKFIELD (WITI) -- Parents of students in Elmbrook School District have been told to be on the lookout for symptoms of whooping cough (pertussis) in their children.

District officials say 20 cases of whooping cough have been confirmed throughout the district. However, the majority of cases has occurred at Pilgrim Park Middle School.

Parents are instructed to be alert for symptoms over the next few weeks. Those symptoms include:

Pertussis is usually spread by repeated indoor face-to-face contact with a person who is sick with pertussis.