Several cases of pertussis recently reported in the Yarmouth and Cumberland-North Yarmouth school systems are part of a statewide surge in the infectious disease this year that is alarming a local pediatrician.

“Pertussis is a horrible disease for a teenager. It can be deadly for an infant. I’m honestly a little bit scared,” said Dr. Laura Blaisdell, a Yarmouth pediatrician at a practice that has many patients from Yarmouth and Cumberland.

Through April 1 of this year, Maine has had 88 pertussis cases, compared with 57 at this time last year, according to the U.S. Centers for Disease Control and Prevention.

Blaisdell said Maine’s high rates of unvaccinated schoolchildren and the pertussis vaccine’s waning effectiveness for teenagers, especially those who don’t receive a booster shot, are the reasons why the disease has come back in Maine.

Greely High School, which enrolls Cumberland and North Yarmouth students in SAD 51, reported Wednesday that two students had tested positive for pertussis this week. The district is investigating whether a third student at the high school also may have contracted the disease, also known as whooping cough. That follows five pertussis cases in Yarmouth schools in March.

Blaisdell’s pediatrics practice at Intermed, which includes three doctors, has treated several cases of pertussis over the past few weeks.

“We are seeing so many cases at this point that we are taking extra precautions to separate infants and adolescents,” Blaisdell said.

In Yarmouth, four cases occurred at the high school and one at the elementary school in March, said Superintendent Andrew Dolloff. On Thursday morning, a sixth case of pertussis was confirmed at Yarmouth High School, according to a letter sent to parents on April 13.

In mid-March, one case of pertussis was reported at Mahoney Middle School in South Portland.

BOOSTER VACCINE COMING

Starting in the fall, Maine will add a seventh-grade booster vaccine that protects against tetanus, diphtheria and pertussis as part of the regimen of vaccines that students should have before entering school. Blaisdell said that will help, but it is only partly effective because Maine allows parents to easily opt their children out of vaccinations by signing a philosophic or religious exemption.

Maine consistently has one of the highest immunization opt-out rates in the country, according to the federal CDC, usually ranking in the top 10 for unvaccinated students.

The Legislature passed a bill in 2015 that would have required parents to consult with a medical professional before opting out of vaccinating their children. Gov. Paul LePage vetoed the measure, and an override vote fell short.

No vaccination bills are pending in the current legislative session, and Blaisdell said the political climate in Augusta needs to change before vaccine advocates try again.

Research has shown that vaccines are overwhelmingly safe, but there are pockets of parents who believe otherwise. A 1998 British study often cited by vaccination critics that claimed to link autism to vaccines has been debunked and retracted.

The persistent, unfounded fears that vaccines are unsafe not only result in many unvaccinated children, but also threaten public health by creating favorable conditions for the return of infectious diseases such as pertussis, Blaisdell said.

“Maine needs to realize that philosophical exemptions should be a thing of the past,” she said.

VACATION COMES AT A GOOD TIME

Jeff Porter, SAD 51 superintendent, said there also was a pertussis case at Mabel I. Wilson elementary school in December, and that the booster shot for middle school students is definitely needed.

“Overall, we’ve had a lot of illnesses over the past month. We will be doing extra cleaning and disinfecting when the students are gone,” Porter said. “School vacation couldn’t have come at a better time.”

April vacation starts Friday at SAD 51 schools.

The kindergarten vaccination opt-out rate at the Mabel Wilson school was 6.6 percent in 2015-16, compared with the statewide opt-out average of 4 percent, according to a state database. For first-graders at Mabel Wilson that year, the opt-out rate was 9 percent. The 2016-17 school-by-school state database will be available later this spring.

Maine has lagged behind most other states in requiring the second dose of Tdap, as the pertussis vaccine is called. Maine and South Dakota recently became the last states in the nation to require the middle school booster shot, according to the Immunization Action Coalition, a nonprofit organization at the University of Minnesota.

MAINE ABOVE NATIONAL AVERAGE

Maine had 21.1 cases of pertussis per 100,000 people in 2015, compared with the national average of 10.3, the most recent national comparison available. The state has consistently ranked far above the national average in pertussis cases, although the numbers vary widely by year.

Pertussis cases in Maine surged to 737 in 2012, or nearly 60 cases per 100,000 people, and declined to 256 cases in 2016, or roughly 20 cases per 100,000 people. The five-year average was 332, about 26 cases per 100,000 people, according to the Maine Center for Disease Control and Prevention.

Blaisdell said pertussis can cause many problems, including ruptured blood vessels in the eyes from violent coughing, and repeated vomiting. The cough can last many weeks.

“It’s called the 100-day cough,” she said.

Blaisdell said she believes Maine is susceptible to a pertussis outbreak similar to what happened in California in 2010, when there were 9,000 cases and 10 infant deaths. There also was a whooping cough outbreak in California in 2014.

“The only way to protect the vital public domain of schools is to make sure all who share that space together are immunized,” Blaisdell said. “This is the urgent work of our public health practitioners and our elected officials.”

Joe Lawlor can be contcated at 791-6376 or at:

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