Washington is in the midst of its worst pertussis outbreak since the 1940s. As of mid-May, there have been over 1,500 cases in the state, more than 10 times as many as last year. Pertussis, or whooping cough, has been seen in 28 counties in both Eastern and Western Washington. The current epidemic is likely to continue into the summer, when most cases are typically diagnosed.
In April, Gov. Christine Gregoire and Health Secretary Mary Selecky officially declared this an epidemic. In addition, they have been raising awareness and making thousands of doses of vaccine available to the public. This is good news for Washingtonians, as similar efforts during a pertussis outbreak in California in 2010 reduced new infections to the state’s typically low rates.
Pertussis is a bacterial respiratory infection that at first appears similar to a common cold. Symptoms include cough, runny nose, low-grade fever or no fever at all. But instead of resolving after a week or two as most colds do, the cough accelerates, coming in bursts or paroxysms. 
Young children may gasp for breath in between such paroxysms, making the typical, high-pitched “whoop” sound, but most people with pertussis will never “whoop” at all. This is because adults and older children have larger airways and may have partial immunity from previous vaccination. Any cough lasting longer than two weeks in this age group should be evaluated for pertussis by a health professional promptly. 
Treatment typically consists of a short course of antibiotics, which are usually inexpensive and well tolerated, and can lessen the severity of cough and decrease contagiousness. Pertussis is highly contagious, so those diagnosed and treated with the disease are encouraged to stay home for five days before returning to school or work — or for three weeks if not treated.
Infants less than 1 year of age, however, are more seriously affected than older children and adults. What may be more of a nuisance in adults can actually be fatal in infants. In this age group, any cough, difficulty breathing or decreased feeding should be evaluated. Fortunately there have not been any deaths reported this year in Western Washington, though several young children have been hospitalized, and two deaths due to pertussis in infants occurred last year.
While newborns are too young to receive the pertussis vaccine, we can protect them by immunizing everyone around them, creating a “cocoon” of protection for each child. This includes parents, grandparents, older siblings and other caregivers. Pregnant women are especially encouraged to get vaccinated after 20 weeks of gestation, or during the third trimester, which results in a particularly robust immunity for the mother and transfers protective antibodies to the unborn child through the placenta.
Vaccination is the most powerful tool to prevent infection, with better than 90 percent protection rates. And even those who still get whooping cough despite being fully vaccinated tend to have milder forms of the disease. For children, this means a five-shot series of DTaP (Diphtheria, Tetanus, and acellular Pertussis vaccine), as well as a dose of Tdap at ages 12 and 19. 
Adults should get a one-time Tdap booster if they have not had one before, even if they are current with their regular Td boosters for tetanus and diphtheria. The state of Washington and most doctors’ offices keep immunization records and can help identify who is due for a Tdap booster. In addition, Washington’s Department of Health, King County and Snohomish County have made vaccines available free of charge to those who lack health insurance or cannot afford them.
Unfortunately, many Washingtonians are not fully immunized. A recent study showed that Washington has the highest rate in the nation of parents voluntarily exempting their children from recommended vaccines, either due to concern for side effects or for philosophical reasons. While pertussis rates typically climb every five years or so, this rate of under-vaccination has likely contributed to the severity of the current epidemic.
Health officials hope local and national media attention will encourage Washingtonians to get up to date on their immunizations. Along with hand washing, staying home from work or school, and seeing your health care provider, vaccination can both help control the current epidemic and prevent future outbreaks. 
Zubin Vasavada, M.D., is a board-certified family physician and clinical instructor at the UW Neighborhood Clinic – Ravenna in Seattle’s University District. For more information, call (206) 520-5000 or visit uwmedicine.org/uwnc.