The number of whooping cough cases in Maine is on the rise, mirroring a nationwide trend that health officials attribute in part to children and adults failing to get booster shots every 10 years.

Health officials began noticing an increase in whooping cough — pertussis — cases within the past year, mainly in Maine’s northern counties. This month, an outbreak of eight cases in children was reported in Skowhegan, and Scarborough school officials notified parents of four cases in the elementary and middle schools.

The Maine Center for Disease Control and Prevention has confirmed 67 cases this year, up 34 percent from the 50 cases reported through May 17 last year. Only 53 cases were reported for all of 2010.

Whooping cough is a highly communicable respiratory disease that causes long coughing fits and is characterized by a whooping sound as a person gasps for air. People of any age can get it, but cases are seen increasingly in children and adults who don’t receive vaccine boosters at the age of 11.

Children typically are vaccinated for whooping cough as part of a series of childhood immunizations, but the vaccine loses effectiveness over time. Doctors recommend that adults get the vaccine booster every 10 years.

Parents who enroll a student in kindergarten in Maine are asked to show that the child has been vaccinated for diphtheria, tetanus, pertussis, measles, mumps, rubella, polio and chickenpox. Parents can sign a form exempting their child for medical, philosophical or religious reasons. Nearly 4 percent of Maine students attend school without vaccinations.

Dr. Stephen Sears, the state epidemiologist, said Maine is not alone in seeing a jump in whooping cough in the past year.

Last month, Washington state health officials declared a pertussis epidemic. They have reported 1,484 cases so far this year. Last year, they had 965 cases, and in 2010 they had 608 cases.

The 67 cases in Maine so far this year includes 13 in Cumberland County, 10 in York County and 12 in Somerset County.

Last year, a total of 205 cases were reported in Maine, far exceeding the 53 reported cases in 2010 and the 10-year average of 82 cases per year.

“People thought this disease was gone, and we know it’s not,” Sears said.

He said the most effective way to protect against whooping cough is vaccination. Most children get the initial vaccination, but only 60 percent to 70 percent receive the booster shot around age 11, he said.

“We’re really trying to get the message out that it’s pretty much everywhere,” he said.

Federal health officials say pertussis isn’t spreading because of an anti-vaccine movement. Possible reasons for the recent spike include better diagnosis in teenagers and adults, more reporting of cases to health officials, and people who do not receive booster shots.

Dr. Ali Kopelman of Saco PrimeCare Pediatrics said that in the past year she has treated 10 children with pertussis, including three in the past three months. All of the patients were ages 4 to 10 and were up to date on vaccinations.

People who are vaccinated can still get whooping cough, but their symptoms are less severe, she said.

“If it’s in the community and you’re around it, there’s a good chance you’ll get it,” Kopelman said.

She said whooping cough is especially serious for infants because coughing can be severe enough to stop their breathing. Infants are most often exposed to pertussis by adults.

Before this month, Scarborough school officials had not had to notify parents of pertussis cases for about five years. Students with pertussis have to stay at home for five days.

Patty Bolduc, a school nurse, said a letter about the pertussis cases was sent to parents to heighten awareness of the increasing number of cases statewide. The school recommends that parents make sure their children are up to date on the vaccine. Less than 1 percent of Scarborough students are exempt from the vaccination requirement.

“I think what we’re seeing in Scarborough is what is being seen around the state,” Bolduc said.

Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.