A University College London–led team finds a very low risk of pediatric intensive care unit (PICU) admission and death from COVID-19 and multisystem inflammatory syndrome in children (MIS-C) during the first 2 years of the pandemic, with the highest risk among children with complex medical problems and neurodisabilities.
The researchers conducted a population-level analysis of hospitalizations after COVID-19 infection in England among youth 0 to 17 years old from February 1, 2020, to January 31, 2022. They linked national hospital data with data on COVID-19 testing, vaccination, PICU admissions, and death.
The research was published yesterday in JAMA Pediatrics.
Hospitalizations highest in young, minorities
A total of 10,540 hospitalizations due to COVID-19 and 997 due to MIS-C were identified, with numbers of both declining during the second year of the pandemic. Of 10,540 hospitalized children and adolescents, 4.3% required PICU admission for COVID-19, falling from 9.9% in wild-type cases to 6.1% with Alpha variant infections, 3.4% with Delta, and 1.7% with Omicron.
Overall, 62.1% of hospitalizations for COVID-19 were among children younger than 5 years. The age distribution varied over time, with those aged 0 to 5 making up a higher proportion during Omicron than during previous variants.
Youth from deprived neighborhoods and those who were Asian, Black, or multiracial were overrepresented in hospitalizations throughout the pandemic. Medical comorbidities were noted in 43.9% of children hospitalized with COVID-19, ranging from 29.1% among children younger than 5 to 69.5% among those 12 to 17 years old.
Of children and adolescents with chronic conditions hospitalized with COVID-19, 8.6% required PICU admission, compared with 0.9% in those without comorbidities. PICU admission increased from 3.9% with underlying conditions affecting one body system to 12.2% in those with more chronic conditions and 17.0% for those with life-limiting neurodisabilities. The proportion of children requiring PICU admission fell as the pandemic progressed among those with and without comorbidities.
After adjusting for the presence of any chronic condition, youth aged 5 to 17 years were at significantly greater odds of PICU admission for COVID-19 than those younger than 5, as were children who were Asian, Black, or of unspecified race compared with their White peers.
No MIS-C deaths
From May 2021 to January 2022, there were fewer than 20 hospitalizations a month due to MIS-C per 100,000 COVID-19 cases. A total of 61.6% of hospitalizations with MIS-C occurred among boys, 58.5% were among children aged 5 to 11 years, and 29.2% were among those aged 12 to 17.
A total of 69.7% of MIS-C hospitalizations occurred among youth with an underlying disease, but a high proportion of these cases may have been acute complications. After excluding hematologic and noncongenital cardiac conditions (common acute manifestations of MIS-C), 35.6% of hospitalized patients had a previous comorbidity. Overall, 54.8% of MIS-C hospitalizations occurred among never-before-hospitalized children.
A total of 43.8% MIS-C patients required PICU admission, 46.4% of them aged 12 to 17 and 34.1% younger than 5. This proportion declined over time, from 58.8% during wild-type dominance to 51.8% during Alpha, 45.3% during Delta, and 31.1% amid Omicron.
After adjusting for the presence of any comorbidity, girls were linked to a higher likelihood of PICU admission, as were youth aged 12 to 17 years versus those younger than 5 and Asian and White children.
Children and adolescents with multiple medical problems were most at risk regardless of SARS-CoV-2 variant, and should be central to public health measures as further variants emerge.
Forty-eight children and adolescents died of COVID-19 within 28 days of hospitalization, but none died of MIS-C (data on MIS-C deaths were available only from November 2020 onward). The risk of severe COVID-19 was tied to underlying medical conditions and neurodisabilities, regardless of variant. Results were similar when the analysis excluded previously infected or vaccinated children.
Complex approaches required
The study authors noted that only 1.7% of children were admitted to PICUs for COVID-19 by the Omicron period. "These falls may reflect multiple mechanisms, including lower disease severity with more recent variants, changes in clinical practice and thresholds for hospitalization and PICU admission as learning occurred across the pandemic, and higher incidental infections in hospitalized children and adolescents at times of high community infection rates," they wrote.
"Children and adolescents with multiple medical problems were most at risk regardless of SARS-CoV-2 variant, and should be central to public health measures as further variants emerge," the researchers concluded.
In a commentary in the same journal, Kathleen Chiotos, MD, and Julie Fitzgerald, MD, PhD, both of Children's Hospital Philadelphia, said that what is not measured in the report "represents our greatest imperative: addressing the decrement in child physical and mental health indirectly related to the COVID-19 pandemic and the resulting mitigation strategies."
Overcoming these pandemic effects, they said, will require complex solutions such as expanding child mental health services, improving access to routine childhood vaccinations and preventive healthcare, and investments in community- and public school–based programs—especially those focused on disadvantaged groups.
"We must now look beyond counts of pediatric COVID-19 cases to understand, measure, and reduce the deleterious indirect impacts of the COVID-19 pandemic on children—and at a time when many have declared the COVID-19 pandemic 'over,' our efforts to overcome these secondary pandemic effects have only just begun," they wrote.
