“And we know there are a lot more out there that haven’t been diagnosed yet,” Abplanalp said.

Six cases were reported in Lewis County in 2011, which is the average number for an entire year.

In 2010, Lewis County had an outbreak of 42 whooping cough cases.

Abplanalp said the county health department is expecting more cases than the last outbreak in 2010.

Statewide, 1,132 whooping cough cases have been reported through April 28 compared to 117 at the same time last year. The outbreak is on pace to reach more than 3,000 cases, which has not been seen in more than 60 years, according to state officials.

Nearly three-quarters of all cases this year have occurred in Snohomish, Skagit, Pierce, King and Clark counties. Twelve counties have reported no whooping cough cases, according to state officials.

Gregoire made $90,000 available from the state’s emergency fund on Thursday to help strengthen public awareness efforts about the needed vaccination. The state Department of Health is already prepared to spend $21,000 to fight the outbreak.

The state is also using federal funds, designated for other immunizations, to buy more than 27,000 doses of pertussis vaccine for uninsured adults.

Cantwell and state Department of Health Secretary Mary Selecky called for the CDC to send Epidemic Aid investigators and epidemiologists to study the disease Friday.

“A swift response is critical to stem this outbreak and save lives,” Cantwell said in a prepared statement. “With dozens of new cases occurring every week, there is no time to waste. That’s why we’re making sure our state health officials have every available resource to stem this outbreak of whooping cough. These CDC investigators will help us pinpoint and eliminate the spread.”

Abplanalp said it is important for adults and children over 11 years of age to get a whooping cough booster, known as the Tdap vaccine.

Whooping cough is a contagious airborne disease that spreads through face-to-face contact with an infected person, and it is most dangerous for infants, pregnant women and elderly people.

Of the 21 reported cases in Lewis County, Abplanalp said a majority are children 18 years old and younger, including two infants.

Abplanalp said infants should get immunized after they are two months old, then get a series of four more shots at four months old, six months old, 12 to 18 months old and four to six years old.

Another booster shot is needed when a child turns 11 years old, Abplanalp said.

The state health department recommends women get vaccinated after 20 weeks of pregnancy.

To receive the Tdap vaccine, Abplanalp suggests people call their healthcare providers or contact the county health department at 740-1223.