Health officials are reporting an outbreak of whooping cough in Snohomish County, with more cases during the first two months of this year than in all of 2010.

Last year, there were 25 cases of whooping cough, also known as pertussis, in Snohomish County.

This year, 43 cases have been

confirmed and an additional 23 suspected cases have been reported, said Dr. Gary Goldbaum, health officer for the Snohomish Health District.

“It is a reminder that immunization is critical — that’s the key to keep children from dying from this disease,” Goldbaum said.

Whooping cough can kill newborns because it can restrict their breathing, he said.

The growth in the number of cases locally is part of a national trend, with 21,000 cases reported to the federal Centers for Disease Control and Prevention last year.

“That’s the highest number of reports in many years,” Goldbaum said.

The increase in cases in Snohomish County and Washington state began about four months ago, he said.

Three doses of the vaccine are recommended for infants, administered when they are two, four and six months of age, Goldbaum said. A booster shot is recommended at age 5.

What has recently changed is a federal recommendation for anyone 18 and over to get another vaccination, especially if they are around infants too young to get the shot, he said.

The cases in Snohomish County during the first two months of the year show that all age groups have been affected.

No one age group has been disproportionally hit with the bacterial disease. And there are no clusters of cases in any geographic area. “It’s really across the county,” Goldbaum said.

The disease is known for its classic “whoop” when a child is coughing. But as children grow older and become adults, the sound of the cough can change.

That’s why anyone with an unusual cough, particularly if it lasts more than a week, should be checked out at a clinic, Goldbaum said. “It doesn’t go away by itself that quickly.”

In some areas of the United States, the number of cases has risen so sharply that the disease has been labeled an epidemic.

California reported 8,383 cases of pertussis last year, including 10 infant deaths.

Two Washington state infants died from the disease in 2010, one each in Whatcom and Grant counties, said Donn Moyer, a state Department of Health spokesman.

The number of cases in Snohomish County in recent years has ranged from 21 in 2006 to 47 in 2008.

“We’ve got a lot of cases. That is of great concern,” Goldbaum said. “We’re particularly worried about the possibilities that newborns and infants could be exposed.”

Sharon Salyer: 425-339-3486 or salyer@heraldnet.com .

Symptoms of whooping cough

Whooping cough or pertussis can cause serious illness in infants, children and adults. The disease usually starts with coldlike symptoms and may include a mild cough or fever. After one to two weeks, severe coughing can begin. Unlike the common cold, pertussis can become a series of coughing fits that continues for weeks.

In infants, the cough can be minimal. It may cause apnea in infants, a pause in the child’s breathing pattern.

Pertussis is most dangerous for babies. More than half of infants younger than 1 year of age who get the disease must be hospitalized.

Pertussis can cause repeated violent and rapid coughing, until the air is gone from the lungs and the patient is forced to inhale with a loud “whooping” sound. However, older children and adults may not experience the “whoop.”

Source: Centers for Disease Control and Prevention

More info

n From the federal Centers for Disease Control and Prevention: http://tinyurl.com/6jpggzg

n From the Immunization Coalition: http://tinyurl.com/6b6b6by

n Whooping cough doesn’t always sound the same. Here are some sounds files and a video to help parents know if their child has whooping cough: www.whoopingcough.net/symptoms.htm