An infant recently arrived at Maine Medical Center in Portland coughing and vomiting uncontrollably. The diagnosis was whooping cough, a highly contagious respiratory disease that’s breaking out in pockets across Maine.
Most of the 80 cases reported in a surge of whooping cough, or pertussis, in the state this year have struck middle school-aged children. In four cases, children under 6 months old were sickened.
The baby at MMC was treated with antibiotics and recovered, said Leah Mallory, a pediatric hospitalist at MMC.
For other babies, the unrelenting cough can prove life-threatening, according to Dr. Lawrence Losey, a pediatrician at Parkview Adventist Medical Center in Brunswick.
“They are coughing so hard and so long that they run out of oxygen and it can cause brain damage and seizures,” he said.
Babies — who don’t typically exhibit the characteristic “whooping” sound as they gasp for air — are vaccinated against pertussis with a series of shots starting at 2 months of age. Children too young for the shots or who haven’t built up enough immunity often catch the disease from a loved one who was never vaccinated or failed to stay current with booster shots, Losey said.
“Just over 60 percent of infant pertussis is gotten from a family member; half of those are from mom,” said Losey, who was recognized last month by the Maine Center for Disease Control and Prevention for his work in childhood immunization.
The danger pertussis poses to babies is one reason public health officials are pushing for better vaccination rates in Maine.
Cases of whooping cough are up significantly from last year. So far this year, there have been 80 cases reported statewide, according to the Maine Center for Disease Control and Prevention. During the same period last year, 49 cases were reported.
The spike in pertussis first cropped up in northern Maine, followed by outbreaks at schools in Skowhegan and Scarborough. Most cases this year have been reported in Somerset, Cumberland, York and Penobscot counties.
The rise mirrors a nationwide trend. Washington state has declared an epidemic of pertussis with more than 1,000 cases this year, the most in at least three decades.
Washington also has one of the highest rates in the country of parents choosing not to vaccinate their kids. Washington and Maine are among 20 states that allow parents to exempt their children from school-required immunizations based on philosophical objections.
Without an exemption, kindergarten students in Maine must be vaccinated against pertussis, diphtheria, tetanus, measles, mumps, rubella, polio and chickenpox. About 3.5 percent of Maine students attended school in 2009-10 without a vaccination, with the majority of parents citing religious and philosophical objections. Some cited medical reasons.
The exemption rate inched up from 3.33 percent the previous year, but remained lower than a peak rate of more than 4 percent in 2007-08.
Parents who skip vaccines say they object to the number of shots and fear a link between immunization and autism, according to a 2008 report by the Muskie School of Public Service.
The pertussis outbreaks are fueling debate about allowing parents to opt out of vaccinating their children, even as health officials say several factors are responsible.
In Vermont, lawmakers recently struck down an effort to get rid of philosophical exemptions, but upheld a requirement that parents sign a document acknowledging the risk their decision not to vaccinate poses to the community.
Last year, Washington passed a bill requiring parents to prove they had consulted a doctor about the benefits and risks of immunization before claiming an exemption.
Maine is one of seven states that imposes no restrictions on claiming philosophical exemptions for vaccinations.
“People with common beliefs about immunization can cluster and that causes a public health concern,” said Caroline Zimmerman, staff coordinator for the Maine Immunization Coalition, a collection of health care providers, consumers, drug companies and others working to reduce vaccine-preventable disease.
“Maine used to be a leader when it came to [childhood] immunizations,” she said. “We were fifth in the nation at one point; now we’re 31st.”
Worries about the cost of immunizations prompted Maine lawmakers in 2010 to pursue free vaccines for children. A new statewide program that took effect in January purchases vaccines at a bulk rate with funds collected through an assessment on health insurers and other entities.
Nationally, about 90 percent of children aged 19 to 35 months in the United States are vaccinated against bacteria and viruses that once routinely sickened or killed many Americans. In some ways, the public vaccination effort has become a victim of its own success, Losey said.
“The young people growing up, and even many of their families, do not understand what these diseases are that we’re immunizing people for,” he said. “They don’t realize how serious and severe they can be.”
Parents shielding their kids from vaccinations is just one driver behind this year’s pertussis outbreak, according to Dr. Stephen Sears, state epidemiologist. Some children may get the initial shot but never go back to complete the series, he said. Plus, only about 60 percent of kids get the required booster shot at age 11.
Still other children catch whooping cough despite being vaccinated, he said. The pertussis vaccine wears off over time but still slashes the risk of catching and spreading the disease and generally leads to a milder case, Sears said.
“Although we’re seeing pertussis, there are a lot of people who are not getting it,” he said.
Pertussis is treated with antibiotics, which do little to alleviate coughing fits that can last up to three months, but do greatly reduce the likelihood of spreading the disease to others.
Older kids and adults also are advised to get pertussis booster shots along with their tetanus immunization.