Half of newly diagnosed coronavirus cases in Washington State are in people under 40
Half of new coronavirus infections in Washington are now occurring in people under the age of 40, a marked shift from earlier in the epidemic when more than two-thirds of those testing positive were in older age groups.
A new analysis finds that by early May, 39% of confirmed cases statewide were among people age 20 to 39, while those 19 and younger accounted for 11%.
The trend is concerning and should be kept in mind as more counties begin to ease restrictions and reopen businesses, said Seattle epidemiologist Judith Malmgren, who is affiliated with the University of Washington and is lead author of the report.
Though younger people are less likely to die or be hospitalized with the virus, they can still suffer serious illness — as underscored by recent reports of a rare, life-threatening inflammatory syndrome in children. And even if younger people don’t get sick, they can pass the virus on to others who are more vulnerable.
“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.
Malmgren and her colleagues don’t attempt to tease out all the reasons for the shift in age distribution, but one factor is obvious, she said. “Being a Seattleite, just walking around and seeing so many young people congregating without wearing masks, I thought: ‘This is interesting.’ ”
Malmgren was also intrigued by the epidemic’s overall trajectory in the state, with cases peaking on March 22, declining for a few weeks, then hitting a plateau with an average of about 200 cases a day for more than a month. She decided to dig more deeply into those numbers to see what patterns might emerge.
It’s the kind of analysis that will become increasingly important as society reopens and health officials will need to quickly identify new cases, hot spots, and groups at high risk in order to keep the virus from exploding again, Malmgren said.
“While disease modeling was helpful at the beginning of the epidemic, a more granular approach to profiling case characteristics is paramount to evaluate where the disease is now in the population and to plan accordingly,” she said. [Continue reading…]