© Provided by WMTW Portland ME Freeport High School

The number of cases of pertussis, or whooping cough, at Freeport High School continues to grow.

The superintendent of Regional School Unit 5 said Friday that there are 12 confirmed cases, up from three last week.

School officials said they hope the winter holiday break will stop the spread.

Whooping cough is spread from person to person through sneezing or coughing.

Symptoms of whooping cough typically start out like the common cold, with a sore throat, runny nose and low-grade fever. Symptoms can worsen after a week or two.

The hallmark signs of whooping cough include uncontrollable coughing fits and a high-pitched whooping sound when breathing in after a coughing episode.

In March, researchers found Maine has the highest rate of pertussis in the country. It is more than eight times the national average.

READ THE FULL STORY:12 cases of whooping cough reported at Maine high school

CHECK OUT WMTW:Stay informed with the latest Portland news and weather from the team at WMTW. Browse the newest Portland, Maine, news stories and stay in the know.