Last month, as Delta surged, the incidence of Covid in children rose earlier in the summer – to 16.2 cases per 100,000 children ages 4 and under; 28.5 cases per 100,000 children ages 5 to 11; and 32.7 cases per 100,000 children ages 12 to 17.
That rate represented a sharp spike from a June low of 1.7 per 100,000 children ages 4 and under; 1.9 cases per 100,000 children ages 5 to 11; and 2.9 per 100,000 children between the ages of 12 and 17. It was still below the peak incidence of childhood cases last January.
The proportion of Covid patients under 17 admitted to intensive care units ranged from 10 to 25 percent from August 2020 to June last year, hovering around 20 percent by July 2021, according to the CDC study.
In a second study, researchers analyzed data from the Covid-Net surveillance network, which includes information on hospitalizations in 99 counties in 14 states.
Over the course of the pandemic — or from March 1, 2020 to August 14, 2021 — there were 49.7 Covid-related hospitalizations per 100,000 children and adolescents, the researchers found.
But weekly rates have been rising since July. During the week ending August 14, there were 1.4 Covid-related hospitalizations for every 100,000 children, compared to 0.3 in late June and early July. (That remains slightly below the weekly peak rate of 1.5 hospitalizations per 100,000 children, beginning January 2021, in the wave of cases after the holidays.)
The number of hospital admissions has increased most for children aged 4 years or younger. In the week ending August 14, there were 1.9 hospitalizations per 100,000 children in that age group, nearly 10 times the number at the end of June.