So far, at least 169 cases of acute hepatitis have been reported from 11 countries in Europe, and in the United States, in children aged from 1 month to 16 years.

Seventeen children – about 10 percent of the reported cases – have required liver transplants, and one death has been reported.

The symptoms include abdominal pain, diarrhoea, vomiting, jaundice, severe acute hepatitis, and increased levels of liver enzymes.

The viruses that commonly cause acute viral hepatitis have not been detected in any of these cases.

Adenovirus has been detected in at least 74 cases, and this and other hypotheses are being explored.

WHO is working closely with the European Centre for Disease Prevention and Control, and the affected countries, to support ongoing investigations, including additional lab testing.