Portland public schools on Wednesday said they are aware of several confirmed cases of pertussis, commonly known as whooping cough.

News Center Maine (WCSH/WLBZ) reported that there has been one confirmed case at Longfellow Elementary School and a second presumed case. The television station said two students at Lincoln Middle School have been diagnosed with whooping cough, with a third middle school student undergoing testing.

Parents and staff at both schools were notified as was the Maine Center for Disease Control and Prevention. School nurses will continue to monitor the situation and will try to keep families updated.

A Deering High School student was also recently diagnosed and treated with a course of antibiotics. That student has since been allowed to return to school, News Center Maine reported.

Whooping cough is a highly contagious disease. Maine has the highest pertussis rate in the country.

Pertussis is a bacterial infection that produces a violent cough that can trigger vomiting and exhaustion. Babies too young to get vaccines and the elderly are especially vulnerable to serious cases, which can require hospitalization or lead to death. The cough can linger for up to 10 weeks and is treated with antibiotics.