More than 40 Washington residents — including 19 in King County — have died in confirmed cases of influenza this season, according to data from state and county health officials.

And even though there are signs that a moderately severe flu season may have hit its peak, health officials say it’s not too late to benefit from getting a flu shot.

“People shouldn’t confuse flu season peaking with flu season ending,” said Dr. Jeff Duchin, communicable-disease chief for Public Health — Seattle & King County.

“There are a lot of people still getting sick. And there will be a lot more flu illnesses occurring in the community over the next six to eight weeks.”

The number of deaths confirmed by laboratories represents a small fraction of those who will succumb to flu over the course of a season, partly because there is no requirement to report flu deaths.

Duchin said estimates from the Centers for Disease Control and Prevention indicate there are between 20 and 300 flu-related deaths each year in King County alone.

This year’s outbreak may be toward the higher end of that range, he said, but it will be months before enough data are collected and analyzed to have a clear picture.

In figures released Friday, the state Health Department listed 38 lab-confirmed influenza deaths.

But because of the time it takes to confirm and report a case, some counties list higher numbers than the state reports.

Health officials in King County list 19 flu deaths — three more than the state lists for King County. Likewise, Pierce County has confirmed five deaths, three more than the state list includes.

Other counties with multiple confirmed flu fatalities are Snohomish County (seven), Clark County (three) and two each in Skagit and Island counties.

As typically occurs, this year’s influenza has been most dangerous among the elderly. Of the 38 deaths listed by the state, 23 were patients at least 80 years old, while another eight were between 70 and 80.

Jack Broom: jbroom@seattletimes.com