Explainer: Scientists are investigating an outbreak of hepatitis in children in Europe and the United States

People enter the Georgia Children’s Hospital in Augusta, Georgia, U.S., January 14, 2022. REUTERS/Hannah Beier

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LONDON, April 22 (Reuters) – Health authorities around the world are investigating a mysterious rise in severe cases of hepatitis – inflammation of the liver – in young children.

Below is a summary of what is known about the outbreak.

More than 130 cases have been identified, the majority in Britain, which has reported 108 cases since January.

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Other countries, including the United States, Israel, Denmark, Ireland, the Netherlands and Spain, have also reported smaller numbers of cases. Read more

Mild pediatric hepatitis is not unheard of, but cases first raised alarm in Scotland on April 6 as children were very ill. Many even needed liver transplants. Read more

The other concern was that the cases were not linked to the typical viruses usually associated with the disease – hepatitis A, B, C, D and E.

“It’s still a very low number of cases, but these are children, that’s the main concern, and the other thing is the severity,” said Maria Buti, professor of hepatology at Barcelona and President of the European Association for the Study of the Public Health Committee of the Liver, which has been following the outbreak closely with the European Center for Disease Control (ECDC).

The leading theory is viral infection, likely with an adenovirus – a common family of viruses that can cause the common cold, among other conditions.

One type of adenovirus usually causes acute gastroenteritis, and has been reported to cause hepatitis in immunocompromised children, but never before in healthy children.

Public Health Scotland director Jim McMenamin said work was underway to determine if the adenovirus involved had mutated to cause more severe disease, or if it could cause the problems ‘in tandem’ with another virus. , possibly including SARS-CoV-2, the virus that causes COVID-19.

He said 77% of children in Britain had tested positive for adenovirus.

It’s also possible that a new pathogen was involved, or exposure to a toxin, but the geographic spread of cases suggests infection was a more likely explanation, the scientists said.

Any link to COVID-19 vaccines has been ruled out because children in Britain, where the majority of cases have been found, have not been vaccinated.

Other scientists have said reduced immunity due to reduced social mixing during the pandemic could be one explanation.

“It may be an over-response to stimulation of the immune system which is not used to such an insult…it’s a good theory,” said Simon Taylor-Robinson, consultant hepatologist and professor of translational medicine at Imperial. College of London.

Others have warned that adenovirus infections could be a coincidence, as they circulate widely at this time of year. Investigations are ongoing.

Public health alerts in the United States and Europe have asked doctors to be on the lookout for the disease and to test children for adenovirus if they suspect hepatitis.

Symptoms include dark urine, yellowing of the eyes and skin (jaundice), nausea, fatigue, fever, loss of appetite, nausea, vomiting, abdominal pain, light-colored stools, joint pain.

There is no specific treatment for hepatitis, but drugs such as steroids can help, as well as drugs to treat symptoms.

Parents are told to watch out for symptoms and contact a medical professional if they are concerned.

To prevent further spread, the UK Health Safety Agency has urged hand washing and “thorough good respiratory hygiene”, such as catching coughs and sneezes in a tissue.

Experts said the increase in the number of cases had been relatively slow, but warned that more cases were expected.

“If you pay attention to one thing, you see more,” Buti said.

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Reporting by Jennifer Rigby and Natalie Grover in London; Editing by Josephine Mason, Robert Birsel

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