The pertussis outbreak at Freeport High School has spread to 10 students and the district is hoping the pending school vacation will help stop the spread of the disease, which is highly contagious but is easily preventable through vaccination.

Superintendent of Schools Becky Foley notified the Regional School Unit 5 community, which serves the towns of Freeport, Pownal and Durham, about the growing number of cases in an email Thursday. Earlier this month, the district reported that there were three confirmed cases of pertussis, also known as whooping cough, a highly contagious, but preventable disease, at the high school.

A few days later, that number jumped to five cases, and then on Thursday it landed at 10. Pertussis outbreaks in schools are not uncommon, occurring in Portland, Falmouth and Saco schools in 2019.

“Maine Center for Disease Control and Prevention (Maine CDC) have continued to confirm positive test results this week at Freeport High School for pertussis,” Foley wrote. “Currently, there are no other reported cases at any of the other RSU5 schools. We care deeply about our students’ health and we will continue to monitor our students closely for symptoms while at school.”

Foley’s email to the community made no mention of how many cases had been diagnosed in the school of over 500 students, but in a telephone interview Thursday evening she confirmed the 10 cases that the Maine CDC had reported earlier in the day.

Friday will be the district’s last day of school before students and teachers leave for an extended holiday break. Students are scheduled to return Thursday, Jan. 2.

“We are hopeful that the holiday break will provide us with a break in this (pertussis) cycle,” Foley said. “We care very deeply about our students’ health. We want everyone to be healthy and hopefully that will happen over the winter break.”

In her notice to parents and guardians, Foley urges parents to make sure their family’s vaccinations are up to date. She said the “Tdap” booster shot as of 2017 is required of all seventh grade students in the state of Maine. Protection against pertussis from a childhood vaccine decreases over time.

Pertussis is an infection that affects a person’s airways, and spreads easily from person to person by coughing or sneezing. It usually begins with symptoms of a common cold (sore throat, runny nose, mild cough), but often develops into a severe cough that can lead to coughing fits or vomiting. The cough is often worse at night.

Maine’s rate of pertussis is now about eight times the national average, and the state’s low vaccination rate is heightening weaknesses in the vaccine. The potentially life-threatening disease afflicts more Mainers per capita than any other state in the United States with 446 cases reported in 2018.

Maine also has one of the highest vaccination opt-out rates in the nation, as parents forgo school required immunizations for their children. A new law eliminating religious and philosophical exemptions for childhood vaccines was adopted by the Legislature earlier this year, but will be challenged in a statewide referendum scheduled forMarch 3.

Dr. Laura Blaisdell, a Yarmouth-based pediatrician, said the outbreak of pertussis at Freeport High School is not uncommon.

“This is what pediatricians see with pertussis. Schools are a perfect place for a very contagious disease like pertussis to spread. Kids are in close quarters sharing breathing space,” Blaisdell wrote in a text message. “So our kids are getting sick from this once preventable disease.”

Blaisdell is co-chairwoman of Maine Families for Vaccines, which supported the new law that eliminated religious and philosophical exemptions. She is also vice president of the Maine Academy of Pediatricians.

Blaisdell said there is no guarantee that a 13-day holiday break will be sufficient to break the cycle of pertussis from spreading at Freeport High School. She bases that on the fact that it can take up to three weeks after someone is exposed to become sick.

“Pertussis is a very tricky disease to control because a person can remain contagious for weeks,” Blaisdell said.

If a child has a severe cough, sometimes as extreme as gagging, vomiting or having difficult breathing, they should see their doctor. A test can be done to determine if a person has pertussis. If the test comes back positive for pertussis, the should be kept out of school and public places until they have completed five days of antibiotic treatment.

Individuals at high risk for pertussis include infants under the age of 12 months, pregnant women and people with weakened immune systems.