Hepatitis cases in children puzzle health workers

An unusually high number of children around the world are coming down with a rare liver inflammation without a known source. The World Health Organization reported 169 cases of hepatitis globally since October, with nine cases across the United States. Altogether, 17 children have needed emergency liver transplants, and at least one child has died.

What do the patients have in common? Many, but not all, of the children tested positive for a specific strain of adenovirus, which causes cold symptoms. Most of the cases occurred in Europe, with 114 in the United Kingdom, according to the WHO. Investigators have ruled out the COVID-19 vaccine as a cause because most of the infected children had not received it. The WHO said the pandemic and its overall effect on public health might play a role, but it is too soon to tell.

Dig deeper: Read the WHO briefing on the outbreak.