Risk of admission to the pediatric intensive care unit for SARS-CoV-2 delta and omicron infections

Severe acute respiratory syndrome coronavirus-2-related and imputable deaths in children: results from the French pediatric national registry

BACKGROUND

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is responsible for an important mortality rate worldwide. We aimed to evaluate the actual imputability of SARS-CoV-2 on the mortality rate associated with SARS-CoV-2-related illnesses in the pediatric intensive care unit (PICU). Secondary objectives were to identify risk factors for death.

METHODS

This national multicenter comparative study comprised all patients under 18 years old with positive SARS-CoV-2 polymerase chain reactions (PCRs) [acute corona virus disease 2019 (COVID-19) or incidental SARS-CoV-2 infection] and/or pediatric inflammatory multisystem syndrome (PIMS) recorded in the French PICU registry (PICURe) between September 1, 2021, and August 31, 2022. Included patients were classified and compared according to their living status at the end of their PICU stay. Deceased patients were evaluated by four experts in the field of pediatric infectiology and/or pediatric intensive care. The imputability of SARS-CoV-2 as the cause of death was classified into four categories: certain, very probable, possible, or unlikely, and was defined by any of the first three categories.

RESULTS

There were 948 patients included of which 43 died (4.5%). From this, 26 deaths (67%) could be attributed to SARS-CoV-2 infection, with an overall mortality rate of 2.8%. The imputability of death to SARS-CoV-2 was considered certain in only one case (0.1%). Deceased patients suffered more often from comorbidities, especially heart disease, neurological disorders, hematological disease, cancer, and obesity. None of the deceased patients were admitted for pediatric inflammatory multisystem syndrome (PIMS). Mortality risk factors were male gender, cardiac comorbidities, cancer, and acute respiratory distress syndrome.

CONCLUSIONS

SARS-CoV-2 mortality in the French pediatric population was low. Even though the imputability of SARS-CoV-2 on mortality was considered in almost two-thirds of cases, this imputability was considered certain in only one case.

Risk Factors for Severe and Critical Coronavirus Disease 2019 in Children

BACKGROUND

Coronavirus disease 2019 (COVID-19) is generally mild in children; however, severe or critical cases may occur. In this nationwide study, we analyzed clinical manifestations in children diagnosed with severe acute respiratory syndrome coronavirus 2 to identify high-risk groups for severe or critical disease and compared the clinical features between the Delta- and Omicron-dominant periods.

METHODS

Data were retrieved from the National Health Insurance Service (NHIS) database and merged with the Korea Disease Control and Prevention Agency-COVID-19-NHIS cohort, which includes information on COVID-19 cases and vaccination records. We included individuals <20 years old diagnosed with COVID-19 during both periods (Delta: July 25, 2021-January 15, 2022; Omicron: January 16, 2022-March 31, 2022).

RESULTS

Proportion of severe or critical cases was higher during the Delta period than during the Omicron period. The Omicron period saw increased hospitalization for pneumonia and croup and increased likelihood of hospitalization for neurological manifestations. The risk of severe COVID-19 depended on age group (Delta: highest for 12-19 years; Omicron: 0-4 years). This risk was high in children with multiple complex chronic conditions during both periods and with obesity or asthma during the Delta but not during the Omicron period. Two-dose COVID-19 vaccination provided strong protection against severe disease in the Delta period (adjusted odds ratio: 0.20), with reduced effectiveness in the Omicron period (adjusted odds ratio: 0.91). However, it significantly reduced the risk of critical illness (adjusted odds ratio: 0.14).

CONCLUSIONS

These findings can facilitate identification of children at high risk of severe or critical COVID-19, who may require intensive medical support, and development of vaccination policies.

Exploring Factors Influencing Changes in Incidence and Severity of Multisystem Inflammatory Syndrome in Children

Multisystem inflammatory syndrome (MIS-C) is a rare condition associated with COVID-19 affecting children, characterized by severe and aberrant systemic inflammation leading to nonspecific symptoms, such as gastrointestinal, cardiac, respiratory, hematological, and neurological disorders. In the last year, we have experienced a progressive reduction in the incidence and severity of MIS-C, reflecting the worldwide trend. Thus, starting from the overall trend in the disease in different continents, we reviewed the literature, hypothesizing the potential influencing factors contributing to the reduction in cases and the severity of MIS-C, particularly the vaccination campaign, the spread of different SARS-CoV-2 variants (VOCs), and the changes in human immunological response. The decrease in the severity of MIS-C and its incidence seem to be related to a combination of different factors rather than a single cause. Maturation of an immunological memory to SARS-CoV-2 over time, the implication of mutations of key amino acids of S protein in VOCs, and the overall immune response elicited by vaccination over the loss of neutralization of vaccines to VOCs seem to play an important role in this change.