As whooping cough rates continue to rise across the state, health officials are urging anyone who spends time around babies to get vaccinated.
"They are the part of the population we want to draw the firmest circle around because they're limited in their immunity," said Sandy Owen, preventive health services director for the Benton Franklin Health District.
And even though adults may have gotten all of their required booster shots as children or adolescents, the immunity from those shots wanes over time. So health officials recommend that adults get a booster now if they haven't already.
Whooping cough, also known as pertussis, is a highly contagious respiratory illness caused by Bordatella pertussis bacteria, and has symptoms similar to a nasty cold -- sneezing, runny nose, fever and cough.
It's the cough that makes pertussis distinctive. Children tend to make a whooping sound with a pertussis cough because they're struggling to catch their breath, according to a state health department fact sheet.
But the whooping is less prevalent in adults and teenagers, who may just have a prolonged cough that persists for weeks or even a couple of months.
Complications for infants include pneumonia, ear infection, loss of appetite, brain disorders or death.
Adults and teenagers may develop pneumonia or experience problems sleeping, urine leakage or broken ribs from severe coughing.
The disease has reached epidemic proportions in Washington this year, with 640 cases reported in 23 counties -- including in Benton and Franklin -- through the end of March, compared to 94 by this time last year, the Department of Health reported earlier this week.
About 82 percent of cases have been in children and teens ages 18 and under. About 7 percent were in children less than a year old; 11 percent in children 1 to 4; 21 percent ages 5 to 9; 25 percent ages 10 to 13; and 18 percent in teens ages 14 to 18, according to health department data.
The most severe outbreaks, where the incidence rate is more than 20 cases per 100,000 people, are in Cowlitz, Skagit, Snohomish, Kittitas, Jefferson and Whatcom counties.
The statewide average incidence rate is 9.5 cases per 100,000 people.
Benton County has had 13 cases reported from January through March this year, making for an incidence rate of 7.5 -- lower than the state average.
But with more cases and a smaller population, Franklin County's 10 reported cases translate into an above-average rate of 13.2.
Health officials say vaccination remains the best means of preventing the illness, even though the vaccine isn't 100 percent effective.
"We're very concerned about the continued rapid increase in reported cases," sid Health Secretary Mary Selecky in a statement this week. "This disease can be very serious for young babies, who often get whooping cough from adults and other family members. We want all teens and adults who haven't had (a booster shot) to be vaccinated to help protect babies that are too young for the vaccine."
Some officials have speculated the rising pertussis rates in Washington could be linked to the state's liberal childhood vaccination exemption laws.
"It's hard to say what may be causing the higher-than-average rate of infection this year, but a possible source could be lower vaccination rates from previous years," Rep. Eileen Cody, D-West Seattle, who also is a nurse, said in a statement Friday.
The federal Centers for Disease Control and Prevention reported in 2011 that Washington had the highest rate of total vaccine exemptions in the nation at 6.2 percent of children.
But a new law that went into effect July 2011 tightened the rules for exemptions in the state, and parents now must have a licensed health care provider sign a form before their children can be exempted from required vaccinations.
Children are required to get five doses of the pertussis vaccine, with the first four doses coming between ages 3 months and 19 months.
They're supposed to get a booster at age 4, but health officials also recommend getting the Tdap -- a combined formula that includes tetanus, diphtheria and pertussis vaccines -- at about age 11 or 12.
Owen said because the immunity wanes, health officials recommend another dose for adults. Current guidelines only suggest adults get one pertussis booster shot.
Tdap is available at most doctor's offices and pharmacies, she said.
Benton and Franklin county residents also can call the health district at 460-4200 to schedule an appointment to be vaccinated.
Melanie Johnston, spokeswoman for Lourdes Health Network in Pasco, said the network's Occupational Health office on Road 100 also is offering the booster shot to any adult who comes in between 7 a.m. and 5:30 p.m., Monday through Friday.
Owen said health insurance pays for the vaccine for many people. Costs vary depending on the provider.
The district has gotten calls from people with questions about whooping cough, and Owen said a common question is whether pregnant women can get a pertussis booster.
The answer is "yes" once they reach 20 weeks of gestation, and Owen said she hopes obstetricians encourage their pregnant patients and partners to get vaccinated before their baby is born to give the infant protection after birth.
"It would be wonderful if obstetricians would start doing this routinely," she said.
Senior citizens also can get the vaccine, although Medicare doesn't typically pay for it, she said.
Anyone under the age of 19 can get vaccinated for free at doctor's offices and clinics that participate in the state's Childhood Vaccine Program.