COVID-19 twice as common among young teens, adolescents than young children

From May to September, the average weekly incidence of COVID-19 was around twice as high among children aged between 12 and 17 years compared with children aged 5 to 11 years, according to data published in MMWR.

Weekly, the older age group averaged 37.4 cases of COVID-19 per 100,000 children compared with 19 cases among children aged 5 to 11 years from, according to Rebecca T. Leeb, PhD, and colleagues from the CDC’s COVID-19 Response Team.

They said the findings “can provide a baseline for monitoring national trends.”

“Monitoring at the local level could inform decision-makers about which mitigation strategies are most effective in preventing the spread of COVID-19 in schools and communities,” they wrote. “CDC’s considerations for schools outline important mitigation strategies for safer reopening for in-person learning. Schools and communities should implement multiple concurrent preventive strategies and adjust mitigation depending on local levels of transmission to reduce COVID-19 disease risk for students, teachers, school staff members, families and the community.”

Their report included data from 277,285 laboratory-confirmed cases of COVID-19 in school-aged children in the United States — 175,782 children aged 12 to 17 years (63%) and 101,503 children aged 5 to 11 years (37%).

“Weekly incidence among school-aged children increased from March 1, peaking at 37.9 cases per 100,000 the week of July 19 (aged 5 to 11 years = 25.7; aged 12 to 17 years = 51.9), plateaued at an average of 34 per 100,000 during July 26 to Aug. 23, decreased to 22.6 per 100,000 the week of Sept. 6, and rebounded to 26.3 per 100,000 the last week for which data are available,” the authors wrote.

Weekly laboratory tests for SARS-CoV-2 among school-aged children more than tripled from 100,081 during the week of May 31 to a peak of 322,227 during the week of July 12, Leeb and colleagues reported. Testing declined during August, and then rose again in September. The authors reported a higher number of tests in teenage children compared with younger children.

Of the 161,387 cases (58%) with complete information, 42% of children were Hispanic, 32% were white and 17% were Black.

Of all school-aged children with confirmed COVID-19, 58% reported at least one symptom, 5% reported no symptoms and information was missing or unknown regarding symptoms in 37% of children, according to the report.

“Overall, 3,240 (1.2%) school-aged children with COVID-19 were hospitalized, including 404 (0.1%) who required ICU admission. Fifty-one (<0.01%) school-aged children died of COVID-19,” Leeb and colleagues wrote.