Clinical features and virologic lineages of COVID-19-associated encephalitis in Taiwanese children during early epidemic wave of omicron in 2022: Report from a medical center

BACKGROUND: A surge of encephalitis was reported in children during the early wave of the omicron epidemic in Taiwan. Information on the COVID-19-associated encephalitis, including epidemiologic features and factors of unfavorable outcomes, remained unclear.

METHODS: A total of 128 hospitalized Taiwanese children with laboratory-confirmed COVID-19 were enrolled between April 01, 2022, and May 31, 2022. The information on demographics and clinical features was abstracted from the medical records. Virologic lineages were determined by sequences of the spike protein. Factors associated with encephalitis and unfavorable outcomes were identified by comparisons to children without encephalitis and with favorable outcomes, respectively.

RESULTS: The leading syndromes associated with COVID-19 in hospitalized children were febrile seizure (20, 15.7%), fever as the solitary symptom (18, 14.1%), and croup syndrome (14, 10.9%). Encephalitis was diagnosed in nine (7.03%) children. When compared to the three leading syndromes, children with encephalitis were at older ages, had greater rates of hypotension, PICU admissions, use of inotropic agents (P < .001 for all above comparisons), mortality (P = .008), and longer hospital stays (P = .016), but not the underlying comorbidities (P = .376). Unfavorable outcomes were identified in 3 (33.3%) of 9 encephalitis cases and associated with a lower Glasgow coma scale, hypotension, and higher C-reactive protein (P < .05 for all). BA.2.3.7 was the dominant sublineage in children with or without encephalitis.

CONCLUSIONS: Omicron BA.2.3.7 can cause fulminant and lethal encephalitis in healthy children. Depressed consciousness and hypotension at presentation were significant risks of unfavorable outcomes for pediatric COVID-19-associated encephalitis.