SACO — Thornton Academy has confirmed two cases of whooping cough.

A letter was sent to parents on Wednesday from school nurse Debbie Prescott stating that the Maine Center for Disease Control informed the school that two high school students had tested positive for pertussis, also known as whooping cough.

Thornton Academy is a private school in Saco. The high school serves publicly funded students from Saco, Dayton and Arundel and also has private pay students from other communities and around the globe.

Pertussis is spread from person to person through the air, according to the Maine CDC. A person can catch pertussis by standing less than three feet away from an infected person who is coughing and sneezing, and a person must breath in droplets from an infected person to get sick, according to the Maine CDC.

The first signs of pertussis are similar to a cold — sneezing, runny nose, fever, and a cough. After one or two weeks the cough becomes worse and occurs in sudden, uncontrollable bursts where one cough follows the next without a break for breath, according to the Maine CDC.

Vaccination is the best way to prevent pertussis, according to the Maine CDC. Good health habits such as washing hands, covering coughs and staying home when sick helps slow the spread of pertussis, according to the Maine CDC.

Confirmed cases of pertussis have been reported in three other Maine school districts this month, according to the Associated Press.

The Maine CDC reported one case of whooping cough at Harrison Middle School in Yarmouth, two cases at Edward Little High School in Auburn and a third case in the Falmouth school system.

There were 410 cases of pertussis confirmed in Maine in 2017, a 58 percent increase from the year before, according to a Maine CDC report.

— Staff Writer Liz Gotthelf can be contacted at 780-9015 or egotthelf@journaltribune.com. The Associated Press contributed to this story.