There is some good news: the H1N1 strain is part of the current vaccine. So unlike the swine flu epidemic in 2009, people can protect themselves this year.
Swine flu is more likely to hit young adults and children than people over 65. Since doctors are not required to report flu cases to the state, officers of the Snohomish County health district say they don't have complete data on the number of flu cases. But at least 12 people have been hospitalized in Snohomish County with the illness.
"The season appears to be in full swing now, and it does appear to be predominantly the H1N1 strain," Dr. Gary Goldbaum, health officer and director of the Snohomish Health District, told The Daily Herald.
State Health Department data, as of mid-December, showed three confirmed flu deaths in Washington in 2013. State data also showed confirmed cases of the flu - nearly all of the H1N1 strain - started to increase around the same time.
In Spokane, about 70 people - most with chronic illness or respiratory issues like asthma - have been hospitalized with the flu.
At least two flu patients with complicating medical conditions have died in Eastern Washington hospitals so far this year.
"It's still too early to tell how serious it is" this year, Dr. Joel McCullough, health officer for the Spokane Regional Health District, told The Spokesman-Review.
Dozens of patients are seeking help for flu symptoms - from sore throat and cough to fever, headaches and body aches - but health officials emphasize it's not too late to get a flu shot.
McCullough said about 35 percent of Spokane residents get the flu shot during an average year. While the vaccine does not guarantee immunity from the flu, it will, in most cases, shorten the duration and lessen the severity of the infection.
McCullough noted that some people avoid getting the shot because they fear it will make them sick.
"That's simply an old wives' tale," he said. "If you get flu right after you get the shot, it's because you were already infected."