Trends in Pediatric Hospital Admissions Caused or Contributed by SARS-CoV-2 Infection in England

Abstract

To investigate the changing characteristics of SARS-CoV-2 related pediatric hospital admissions over time. A national, observational cohort study from 1, July 2020, to August 31, 2023, using English population-linked electronic health records. We identified 45,203 children under 18 years old in whom SARS-CoV-2 either caused or contributed to hospitalization, excluding those admitted with "incidental" infection. Studied outcomes were types of hospitalization and severe hospitalizations involving either critical care or PIMS-TS. There were 45,920 SARS-CoV-2 related hospitalizations in children: 34,870 (75.9%) due to COVID-19; 1,845 (4.0%) due to pediatric inflammatory multisystem syndrome - temporally associated with SARS-CoV-2 (PIMS-TS); 8,330 (18.1%) with SARS-CoV-2 as contributor to admission; and 875 (1.9%) acquired nosocomial SARS-CoV-2 infection. The most notable changes between the first three waves (March 2020 through November 2021) and the omicron era (December 2021 onwards) were: a fall in PIMS-TS from 1,575 of 14,020 (11.2%) to 270 of 31,905 (0.8%); a reduction in critical care use from 1,175 of 14,020 (8.4%) to 1,390 of 31,905 (4.4%); a fall in mortality rate among those hospitalized from 521 per 100,000 to 249 per 100,000; and a drop in the median age of hospitalized children from 4.7 (IQR 0.6,12.3) to 1.1 (IQR 0.3,6.4) years. Of children hospitalized, infants, 10.2% of whom had a recorded underlying health condition, comprised 4,225 of 14,020 (30.1%) admissions 2020 through 2021 and 15,555 of 31,900 (48.8%) since 2022. (p<0.001 for all comparisons). Infants are now the most affected age group by SARS-CoV2, at least partially related to having the least immunity to the virus, and are most vulnerable to respiratory illnesses.