AUBURN — Two school districts have reported students diagnosed with pertussis – whooping cough – in Maine this week.

The Maine Center for Disease Control and Prevention confirmed one case at Harrison Middle School in Yarmouth and two other cases at Edward Little High School in Auburn, school officials said.

Two students at Auburn Middle School are also being monitored, but that school did not have any confirmed cases Wednesday.

Whooping cough is a highly contagious disease that causes violent coughing and can make it hard to breathe. The illness can be deadly, for babies in particular, who may stop breathing and turn blue rather than cough, according to the federal Centers for Disease Control and Prevention. Newborns are too young to be vaccinated against the disease.

According to a Maine CDC report, Maine identified 410 cases in 2017, a 58 percent increase from the year before. Most of those cases were in school-age children, though 25 were in babies less than a year old.

As of November, the latest numbers available, Maine had seen 394 cases of whooping cough in 2018, putting last year on track to meet or exceed 2017’s cases.

Parents are advised to contact their doctor if their child develops a severe cough, has a weakened immune system or lives with someone at high risk, such as a pregnant woman or a baby younger than a year old. It also recommends that parents make sure their children’s vaccinations are up to date.

Whooping cough is spread through coughing, sneezing or sharing breathing space, according to the federal CDC. People can stay contagious for up to two weeks after developing the cough.

Symptoms generally develop five to 10 days after exposure, but they can take up to three weeks to appear.