Half of coronavirus cases in Washington state are under the age of 40

The coronavirus is moving from older to younger residents in Washington state.

Half of the confirmed cases in Washington by early May are under the age of 40, marking a significant shift from the early outbreak of the virus when that age group accounted for just 33 percent of sick residents, according to a new study.

The researchers behind the work are urging health officials to increase awareness and safety efforts targeted toward younger Americans as states continue to reopen.

Even though young people are less likely to be hospitalized with COVID-19, they can still become seriously ill and their lifestyles put them at a greater risk of spreading the disease to others, Seattle epidemiologist Judith Malmgren, who led the study, told the Seattle Times.

“Younger people are the most likely to be socially active, they are the most likely to work in essential professions and have more contact with the public,” Malmgren said.

The report, posted on the reprint server medRxiv, uses the state’s publicly available health data to track the ages of cases between March 1 and May 3, showing the share of cases shifting to younger populations after the total number of infections peaked in late March.

The analysis doesn’t delve into why cases have shifted toward younger patients. But Malmgren said anecdotally she’s observed more younger people in her city out and about without facemasks.

Health officials in the state told the Seattle Times that the trends were the results of early awareness targeting older, vulnerable populations — as younger residents stayed home less often.

“The pattern in who’s getting infected over time reflects people’s behavior,” Dr. Jeff Duchin, a health officer for Seattle & King County, told the paper.