Prevalence of COVID-19, Multisystem Inflammatory Syndrome Hospitalizations in Children

Pediatric hospitalization, child in hospital bed
Pediatric hospitalization, child in hospital bed
Researchers conducted a study to compare hospitalizations due to COVID-19 infection plus multisystem inflammatory syndrome with those due to influenza and respiratory syncytial virus infection among children between 5 and 11 years.

For every 1 COVID-19 hospitalization among children aged between 5 and 11 years, there was 1 hospitalization for multisystem inflammatory syndrome in children (MIS-C) during the winter of 2020 to 2021, according to a research letter published in JAMA Pediatrics.

Researchers performed a cross-sectional study to compare the severity and rate of hospitalizations due to COVID-19 infection plus MIS-C with those due to influenza and respiratory syncytial virus (RSV) infection.

Inpatient data from 1333 community hospitals located in 11 US states were obtained from to identify children diagnosed with COVID-19 infection, influenza, and RSV in the winter of 2020 to 2021. A total of 46 complications were examined, spanning the cardiovascular, respiratory, neurologic, hematologic, kidney, gastrointestinal, and musculoskeletal systems.

Data from 2269 children were included in the final analysis. The mean patient age was 7.6 (SD, 2.0) years and 44% were girls. In regard to patient demographics, 2.2% were Asian or Pacific Islander, 11.7% were Black, 23.8% were Hispanic, 57.5% were nonHispanic White, and 4.8% identified as other.

For every COVID-19 hospitalization there was a corresponding MIS-C hospitalization, and combined hospitalizations for both conditions occurred at a rate of 10.8 per 100,000 children. Although hospitalizations due to influenza and RSV during the same period were significantly decreased, the rate of hospitalization among children with influenza and RSV in 2017 were 17.0 and 6.2 per 100,000, respectively.

The researchers found that the rates of cardiovascular (29.8%; 95% CI, 25.2-34.4; P =.001), hematologic (55.4%; 95% CI, 50.4-60.4; P =.001), kidney (21.9%; 95% CI, 17.7-26.1; P =.001), and gastrointestinal (47.2%; 95% CI, 42.2-52.3; P =.001) complications were significantly increased among children with MIS-C. Children with RSV were found to have significantly increased rates of respiratory complications (75.8%; 95% CI, 71.6-79.9; P =.001). In addition, significantly increased rates of neurologic and musculoskeletal complications were observed among children with COVID-19 infection without MIS (9.6%; 95% CI, 6.5-12.8; P =.03) and those with influenza virus infection (9.5%; 95% CI, 7.8-11.2; P =.001), respectively.

The severity of MIS-C was significantly increased among those who were Asian or Pacific Islander, Black, Hispanic, and those who identified as other. Of these children with MIS, the overall length of hospitalization was significantly increased compared with those who were nonHispanic White (1647 days vs 867 days; P =.047).

This study may have underestimated the national rate and severity of MIS-C as the percentage of children enrolled who were Asian or Pacific Islander,

Black, Hispanic, and other race/ethnicity was 39.4% compared with 50.2% for all US states.

According to the researchers, “[these] finding suggest that MIS-C may not be as rare of a COVID-19 sequela as previously thought.” They concluded, “[this] study may provide important data points for public health planning efforts, including racial and ethnic minority group outreach, to help [decrease] the disease burden of both COVID-19 [complicated by MIS-C] and influenza.”

Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.


Encinosa W, Figueroa J, Elias Y. Severity of hospitalizations from SARS-CoV-2 vs influenza and respiratory syncytial virus infection in children aged 5 to 11 years in 11 US states. JAMA Pediatr. Published online February 21, 2022. doi:10.1001/jamapediatrics.2021.6566