The liver disease, which was first reported in the UK in April, has reportedly resulted in five child deaths in the United States and three in Indonesia, with approximately 26 children requiring liver transplantation.
“To date, 348 probable cases have been reported in 21 countries, with 26 children requiring liver transplantation,” the WHO said in a statement.
“Fifteen countries have reported 5 or fewer cases,” it added.
The United Kingdom International Health Regulations (IHR) reported 10 cases of severe acute hepatitis of unknown aetiology in previously healthy young children (ages 11 months to 5 years old) in Scotland on April 5.
While no cause has been identified thus far, adenovirus, a common family of infections responsible for illnesses ranging from colds to eye infections, is suspected of causing the condition.
Many of the cases had adenovirus detected in blood or plasma samples, but with low viral loads.
However, the World Health Organization stated that “adenovirus has not yet been identified in the liver tissue samples examined and thus could be a coincidental rather than a causal factor.”
The United Kingdom currently leads in cases with approximately 163, and only six countries report more than five cases. The United States announced on Friday that it was looking into 109 possible cases of “unknown origin.”
According to Dr. Philippa Easterbrook, a senior scientist in the WHO’s hepatitis department, adenovirus type 41 was the most common among the cases, causing diarrhoea, vomiting, fever, and respiratory symptoms, according to Global.ca.
More data from the UK, expected this week, will reveal whether the adenovirus is a correlation or a causal factor, according to Easterbrook.
Covid-19 was also found in 18% of the UK cases, and the WHO is investigating how many of the total hepatitis cases had the virus previously.
“An important consideration is the role of Covid, either as a co-infection or past infection,” Easterbrook reportedly said.
The WHO is currently coordinating with the UK Health Security Agency and working closely with all regions in its active investigation.
Hepatitis affects the liver and is distinguished by the appearance of jaundice (yellow eyes), dark urine, and/or pale stools.