WALDOBORO, Maine — The Maine Center for Disease Control and Prevention is investigating a case of pertussis, also known as whooping cough, at Medomak Valley High School, Principal Andrew Cavanaugh and school nurse Sherri Vail wrote in a letter to parents posted on the school’s website on Monday.

Pertussis is an illness that is spread from person to person through coughing and sneezing. It usually begins with symptoms of a common cold and often develops into a severe cough after a few weeks that can last for several weeks or more, according to Maine CDC.

Most children are vaccinated against pertussis but it is still possible for vaccinated children to become ill. Babies are most at risk of serious illness.

To prevent the spread of pertussis in the community, Cavanaugh and Vail recommended that parents whose children have a severe cough that may involve coughing to the point of gagging or vomiting, difficulty breathing or a prolonged cough lasting two weeks or longer contact a healthcare provider.

If the provider suspects pertussis, they will obtain a specimen to be sent for pertussis testing. Children with severe cough, prolonged cough or confirmed pertussis will be prescribed antibiotics and will need to remain at home for five days while taking these antibiotics.

Parents also were advised to make sure they and their children are up to date on pertussis vaccines and that booster shots may be in order for children ages 11 to 18 years and for adults, especially those who have contact with infants and young children.