Children, teens, and young adults are at greater risk for severe complications from COVID-19 than previously thought, according to a study which says those with underlying health conditions are at even greater risk.
"The idea that COVID-19 is sparing of young people is just false," said study coauthor Lawrence Kleinman from Rutgers University in the United States.
According to the study, published in JAMA Pediatrics, children are more likely to get very sick if they have other chronic conditions like obesity.
"It is also important to note that children without chronic illness are also at risk. Parents need to continue to take the virus seriously," Kleinman cautioned.
The study, published in JAMA Pediatrics, is the first to describe the characteristics of seriously ill pediatric COVID-19 patients in North America.
In the research, the scientists assessed 48 children and young adults -- from newborns to 21 years old -- who were admitted to pediatric intensive care units (PICUs) in the US and Canada for COVID-19 in March and April.
The study noted that more than 80 per cent of the children had chronic underlying conditions, such as immune suppression, obesity, diabetes, seizures, or chronic lung disease.
Of these children, 40 per cent depended on technological support due to developmental delays or genetic anomalies, the researchers said.
More than 20 per cent experienced failure of two or more organ systems due to COVID-19, they said, adding that nearly 40 per cent required a breathing tube and ventilator.
At the end of the follow-up period, about 33 percent of the children were still hospitalised due to COVID-19, the scientists reported in the study.
Three of the children still required ventilator support and one of them was still on life support.
The study also noted that two of the children admitted during the three-week study period died.
"This study provides a baseline understanding of the early disease burden of COVID-19 in pediatric patients," said Hariprem Rajasekhar, a pediatric intensivist involved in conducting the study at Robert Wood Johnson Medical School's Department of Pediatrics.
Compared with mortality rates of up to 62 per cent among adults admitted to ICUs for COVID-19, the study noted that the mortality rate for PICU patients is 4.2 per cent.
'This early study shows that COVID-19 can result in a significant disease burden in children but confirms that severe illness is less frequent, and early hospital outcomes in children are better than in adults,' the scientists wrote in the study.
According to Kleinman, doctors are also seeing a new COVID-related syndrome in children.
Citing earlier reports, he said children with COVID-19 may be at risk of heart failure, and a condition termed pediatric multi-system inflammatory syndrome.
"Although our data collection for this study has ended, we continue to develop collaborations with colleagues in our region and across the country to try to understand these more severe complications," Kleinman said.