[Consideration on the emerging acute severe hepatitis cases with unknown etiology in children of some countries]

Since January 2022, acute severe hepatitis cases with unknown etiology in children have occurred in many countries in Europe and the United States, and 43.8% of the cases were positive for human adenovirus (HAdV), and some cases were identified as HAdV-41. However, more evidences including etiology, genomics, liver pathology, and immunohistochemistry are needed to determine the main cause of this outbreak. At present, due to the lack of systematic surveillance and research on hepatitis caused by HAdV infection, it is impossible to determine whether there are similar hepatitis cases occurred in China. It is urgent to carry out HAdV virolgocial surveillance based on clinical symptom, and potential risk of acute severe hepatitis should be studied as soon as possible according to the available relevant clinical, epidemiological and virological data, as well as risk factor information, which will provide scientific and technical support for the prevention and control of HAdV-related diseases.