Understanding Pediatric Critical COVID-19 Disease Around the World

A large, multinational study found more children hospitalized with critical COVID-19 died than was indicated by previous studies.  

Children under 18 represent around 22% of the population in the United States. Yet, just 15% of over 75 million U.S. COVID-19 cases reported to the Centers for Disease Control (CDC) and fewer than 0.2% of over 850,000 reported COVID deaths have occurred in this age group.

During the first year of the pandemic, even as doctors in the United States and United Kingdom began observing the appearance of a startling new condition, multiststem inflammatory syndrome in children (MIS-C), which appeared in kids who had been infected a few weeks prior, it was clear COVID-19 impacted kids and adults very differently – with kids rarely hit as hard.

Only a fraction of U.S. kids who were infected required hospitalization, and even fewer became critically ill, requiring respiratory, cardiovascular or renal support in the pediatric intensive care unit (PICU). Those children also had lower mortality rates compared to adults.

“Patients who got MIS-C maybe needed vasopressors and a ventilator for a couple days, but the often recovered rapidly,” says Todd Karsies, MD, a Critical Care Medicine physician at Nationwide Children’s Hospital.

Low mortality rates among U.S. children and an early focus on MIS-C in pediatric COVID-19 research in the United States, however, obscured the fact that globally, the story was more complicated.

Over 90% of pediatric COVID-19 deaths in the first year of the pandemic occurred in low- or middle-income counties (LMICs), and the highest mortality rates were among children under 1.

To better understand the epidemiology and outcomes of critical pediatric COVID-19 in PICUs in both highly resources, high-income countries (HICs) like the United States and LMICs and begin assessing risk factors for death, over a dozen multinational scientists, including Dr. Karsies, launched the Critical Coronavirus And Kids Epidemiology (CAKE) study, publishing their findings in The Lancet Regional Health – Americas.

“This study organically grew out of a different international project,” says Dr. Karsies. “Since December 2019, we’d already been collecting data from nearly 100 sites in 20 countries on kids who needed to be admitted to the ICU for bronchiolitis. When everything shut down for COVID-19, we were able to build on this existing infrastructure and hit the ground running quickly.”