# Outcome of and Risk Factors for Mortality in Pediatric Coronavirus Disease 2019 Encephalitis During the 2022 Omicron Wave in Taiwan: A National Retrospective Study

## TL;DR

This study found that pediatric COVID-19 encephalitis during the 2022 Omicron wave in Taiwan had high mortality, especially in children under 5 years old.

## Contribution

The study identifies risk factors for mortality in pediatric COVID-19 encephalitis during the Omicron wave in Taiwan.

## Key findings

- 14 out of 75 cases (19%) of pediatric COVID-19 encephalitis resulted in death.
- Children under 5 years old had a higher mortality risk, though the association was not significant in multivariate analysis.
- The disease progressed rapidly, with a median hospital stay of 3 days before death.

## Abstract

During Taiwan's severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron outbreak in 2022, pediatric coronavirus disease 2019 (COVID-19) encephalitis cases surged, resulting in multiple fatalities. We investigated patient characteristics and mortality risk factors.

Using the Brighton Collaboration criteria, we identified 289 suspected pediatric COVID-19 encephalitis cases diagnosed between April and December 2022 by linking the national surveillance, remdesivir application, immunization, and death registries. We analyzed clinical data and viral genotypes, then used univariate and multivariate logistic regressions to assess mortality risk factors.

We identified 75 encephalitis cases: 50 (67%) were male, with a median age of 5 years (interquartile range [IQR]: 3–8 years), 45 (60%) had no comorbidities, and 23 (31%) had received at least 1 dose of the COVID-19 vaccine. The median interval from symptom onset to medical attention was <1 day (IQR: 0–1 day).

Fourteen cases (19%) died after a median hospital stay of 3 days (IQR: 1–5 days). All sequenced viruses matched the circulating Omicron subvariants. In univariate analysis, age <5 years was associated with increased mortality (odds ratio [OR] & 6.05; 95% confidence interval [CI] & 1.53–24.00). Multivariate analysis showed a nonsignificant trend (adjusted OR & 3.64; 95% CI & 0.81–16.40) after adjustment for sex, comorbidities, and vaccination.

During the Omicron wave, the number of pediatric COVID-19 encephalitis cases progressed rapidly and mortality was high, particularly among children <5 years of age, regardless of comorbidities. We recommend COVID-19 vaccination and monitoring for signs of COVID-19 encephalitis in young children.

We retrospectively examined children <18 years old who had COVID-19 encephalitis during the 2022 Omicron outbreak in Taiwan. We found that the disease progressed quickly and was associated with high mortality, particularly for children <5 years old, regardless of comorbidities.