SEATTLE – Hospitals and health officials are reporting a huge upsurge in the number of flu cases in Washington state this month – a time of year when the flu season is usually winding down.
Record numbers of people have tested positive for influenza in Snohomish County this week, and five people have died of the flu in Kitsap County alone since the end of February. As of March 9, there were 93 lab-confirmed deaths from the flu statewide.
This year’s late flu season is due to an unusual progression in the circulation of flu viruses, says Dr. Jeff Duchin, health officer for Public Health Seattle & King County.
During most flu seasons, influenza type A circulates first and is followed by an influenza type B later in the season.
But flu is unpredictable, and this season began with influenza type A/H1N1, and now is being followed by a large, late surge in influenza A/H3N2, with both strains continuing to circulate, Duchin says.
And that’s a problem, he says, because the A/H3N2 strain causes higher rates of severe illness, hospitalizations and deaths than the other types. Current levels of influenza-like illness and reports of lab-confirmed influenza are the highest seen in recent years, he says.
Historically, February has been the peak month for the flu. But this year, it’s clearly later. And Duchin says he expects the flu season to last another four to six weeks – and possibly longer.
For that reason, Duchin says it’s still a good idea to get a flu shot if you haven’t already done so. The current vaccine is 47 percent effective, which which means that if you get the flu vaccine your chances of getting the flu decreases by almost half. And if you do get sick and you’ve been vaccinated, it significantly reduces the length and severity of illness.
A flu shot is especially important for those at higher risk, incluing those over age 65, young children, pregnant women, residents of nursing homes and people with chronic medical conditions such as diabetes or asthma.
People with flu symptoms who see the doctor within two days of their symptoms also can get Tamiflu, which can shorten the duration of the virus.