Likely Cause of Severe Hepatitis in Young Children Discovered

Since late 2020, more than 2000 cases of a severe form of hepatitis have been reported in young children around the world. The condition is not caused by any known hepatitis virus.

Three international teams now report that the primary causal agent might be a specific strain of adeno–associated virus type 2 (AAV2). AAVs are a different species from adenovirus, but they require the presence of adenoviruses or herpesviruses to become pathogenic. AAV2 was found in blood, liver, or stool in virtually all case patients but only rarely in specimens from comparison groups, including patients with other types of acute hepatitis, patients who were immunocompromised, and healthy control children. Antibody studies indicated that this was typically a chi…