NEW YORK－Health officials in several countries are investigating mysterious cases of severe liver disease in children, and they say it may be related to a kind of virus usually associated with colds.

The UK has been investigating at least 74 cases in which children came down with hepatitis, or liver inflammation, the World Health Organization said on Friday.

US health officials say they are looking into nine similar cases. All were in Alabama, but officials say they are looking to see if there are more elsewhere.

"Given the increase in cases reported over the past one month and enhanced case search activities, more cases are likely to be reported in the coming days," WHO officials said in a statement.

The children ranged in age from 1 to 6 years old, and two required liver transplants. The European cases are in a similar age range, though some have been older, WHO officials said.

The WHO first became aware of the unusual illnesses early this month, when they learned of 10 children in Scotland with liver problems. One fell ill in January and nine others in March. All became severely ill and were diagnosed with hepatitis after being taken to the hospital.

The liver processes nutrients, filters the blood and fights infections. The infections caused symptoms such as jaundice, diarrhea and abdominal pain. Hepatitis can be life-threatening if left untreated.

Since then British health officials have identified at least 64 more cases. No one died, but six patients needed liver transplants, the WHO said.

Laboratory testing has ruled out the hepatitis type A, B, C and E viruses that usually cause such illnesses. Officials say they are unaware of international travel or other factors that might have put the children at risk.

However, there has been a recent surge in the spread of adenoviruses, they said.

Triggering other problems

There are dozens of adenoviruses, many of them associated with cold-like symptoms, fever, sore throat and pink eye. But some versions can trigger other problems, including inflammation in the stomach and intestines.

Adenoviruses have previously been linked to hepatitis in children, but mostly in those with weakened immune systems.

Some of the European children tested positive for adenovirus, and some tested positive for COVID-19.But more research is needed to explore any potential associations with specific viruses, the WHO said.

A spate of cases across Europe has heightened concerns in the wake of the UK notification. In Ireland, five cases (confirmed or suspected) have been reported. Similar cases have been reported in Spain.

"These cases are currently being investigated by national authorities," the WHO said.

The WHO "strongly encouraged" member states to identify, investigate and report potential cases that meet the case definition.

Agencies - Xinhua