Table 3. Initial epidemiological data obtained for reported cases of acute severe hepatitis of unknown origin in children 16 years and younger since October 1, 2021.

Indicator	Number of cases	Total cases with testing/procedure	Percent (%)
COVID-19, confirmed by PCR	5	26	23.1
Adenovirus (blood or respiratory sample)	6	25	24.0
Liver biopsy	12	27	44.4
Liver transplant	4	27	14.8

Abbreviations: COVID-19, coronavirus disease 2019; PCR, polymerase chain reaction