Health officials across several countries in Europe and the US are investigating cases of a severe liver disease in children that was first identified in the United Kingdom.
The European Centre for Disease Prevention and Control said on Tuesday it had detected an unspecified number of cases of hepatitis, or liver inflammation, in Denmark, Ireland, the Netherlands and Spain.
The United Kingdom last week said it had identified 74 severe cases since January and the US said nine cases of acute hepatitis had been found in the state of Alabama.
“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,” World Health Organization officials said in a statement last week.
While mild forms of hepatitis are relatively common in children, the severity of the reported cases has given health authorities pause.
“Mild hepatitis is very common in children following a range of viral infections, but what is being seen at the moment is quite different,” said Graham Cooke, a professor of infectious diseases at Imperial College London, told the Associated Press news agency.
Some of the cases in the UK have required specialist care at liver units and a few have needed a liver transplant. The nine children found to have the disease in the US ranged in age from 1 to 6 years old. Two required liver transplants.
UK scientists previously said one of the possible causes they were investigating were adenoviruses, a family of common viruses usually responsible for conditions like pink eye, sore throats, or diarrhoea.
Investigators were also looking into any links between the condition and COVID-19, although some have noted that the condition would likely be more widespread given the prominence of the coronavirus.
Meanwhile, British public health officials ruled out any links to COVID-19 vaccines, saying none of the affected children was vaccinated.
The World Health Organization said no other links had been found between the affected children in the UK and none had recently travelled internationally.
Lab tests are under way to determine if a chemical or toxin may be behind the illness.