Global study notes risk factors for uncommon severe COVID-19 in kids

Boy in hospital on oxygen
Boy in hospital on oxygen

Wavebreakmedia / iStock

A 10-country study of more than 3,000 children who tested positive for COVID-19 in emergency departments (EDs) finds that 3% went on to develop severe disease within 2 weeks, with risk factors being older age, having chronic conditions, and experiencing symptoms longer.

The study was published yesterday in JAMA Network Open.

An international group of scientists report that, among 3,221 children 17 years and younger studied in Argentina, Australia, Canada, Costa Rica, Italy, New Zealand, Paraguay, Singapore, Spain, and the United States, 107 (3.3%) experienced severe outcomes within 2 weeks, and 4 (0.12%) died. Among children discharged home from the ED, the risk was much lower.

The children had visited an ED from Mar 7, 2020, to Jun 15, 2021, a span that mostly predated the Delta variant (B1617.2) and well before the current Omicron (B.1.1.529) variant was detected.

"Fortunately, the risk of developing severe disease in children with COVID-19 discharged from the emergency department is very low," study co-lead author Todd Florin, MD, an associate professor of pediatrics at Northwestern University, said in a University of Calgary news release. "Our findings can provide reassurance to parents and clinicians for children well enough to be managed in the community, while also providing important insights on which children may be at particular risk for severe outcomes."

Asthma not found as a risk factor

Of the 3,221 children treated at one of 41 EDs, 2007 (62.3%) were from the United States, 1,694 (52.6%) were male, and 484 (15.0%) had a self-reported chronic illness. They tended to be young, with a median age of 3 years.

After 14 days of follow-up, 735 children (22.8%) were hospitalized, 107 (3.3%) had severe outcomes, and 4 (0.12%) died. The researchers used a composite measure to define severe outcomes that included intensive interventions during hospitalization, such as positive-pressure ventilation; diagnoses that indicated severe organ impairment; and death.

Characteristics associated with severe outcomes included being aged 5 to 9 years (odds ratio [OR], 1.60 compared with kids younger than 1 year), being age 10 to 17 (OR, 2.39), having a self-reported chronic illness (OR, 2.34), prior episode of pneumonia (OR, 3.15), symptoms starting 4 to 7 days prior to seeking ED care (vs starting 0-3 days before seeking care: OR, 2.22), and country (eg, Canada vs US: OR, 0.11; Costa Rica vs US: OR, 1.76; Spain vs US: OR, 0.51).

The study authors wrote, "Although asthma has been suggested as a risk factor for severe illness in youths with COVID-19, our study, as well as a registry-based study in the United States, did not confirm this association."

Among the 2,510 kids discharged home from the ED after initial testing and who had complete follow-up, 50 (2.0%) were eventually hospitalized and 12 (0.5%) had severe outcomes.

When compared with hospitalized children who tested negative for COVID-19, the risk of severe outcomes was higher among hospitalized COVID-positive patients, with a risk difference of 3.9% (95% confidence interval, 1.1% to 6.9%).

The authors note, "Because participating EDs were located in academic pediatric institutions, we cannot generalize our results to all community EDs nor can we generalize to countries beyond those included in our analysis."

"There are no specific evidence-based treatments and therapies for children at this time, and detailed research data describing outcomes in young people with COVID-19 has been lacking, so this study offers important insights that we believe will be helpful into front-line care providers treating children with COVID-19," said co-senior author Stephen Freedman, MD, a pediatrician at the University of Calgary, in the news release.

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