An unusual rise in liver damage cases in children has been seen in the UK, US and Europe, prompting the World Health Organization (WHO) to closely monitor the situation.
On April 5, the WHO was informed of 10 cases of severe acute hepatitis (inflammation of the liver) in children under the age of 10 in Scotland. Three days later, it had received reports of 74 cases across the UK. Usually in Scotland, there are around 7-8 cases in a year in patients without underlying conditions. Similar cases have been reported in Alabama, with a few cases also being reported in Ireland and Spain.
“Mild hepatitis is very common in children following a range of viral infections, but what is being seen at the moment is quite different," Prof Graham Cooke, NIHR Research Professor of Infectious Diseases, Imperial College London, said in a statement. "Children are experiencing more severe inflammation, in a few cases leading the liver to fail and require transplantation."
In a case report based on the patients first seen in Scotland, doctors note that the severity of the disease seen in the children was "unfortunately remarkable". They report that the children had no significant medical history prior to their admission to hospital, where all of them stayed for at least six days, with three children requiring a liver transplant. Symptoms in the cases were similar.
"For two children, close contact in a household or other setting with two other cases was reported. Symptoms reported include jaundice (eight of nine cases), abdominal pain (seven of nine cases), and nausea and malaise (six of nine cases) leading up to admission," the report, published in Eurosurveillance, notes. "Nearly all of them reported gastrointestinal symptoms including diarrhoea or vomiting and lethargy, but not fever, in the weeks before admission."
The cause of the surge in cases is, as yet, not known. Hepatitis viruses A, B, C, E, and D have been ruled out by laboratory testing, while SARS-CoV-2 (the virus that causes COVID-19) and/or adenoviruses have been detected in several cases, with the WHO noting that there has been an increase in adenovirus activity in the UK. Experts are split as to the cause of the disease, without enough data to go on as yet, though a virus of some description seems likely.
“When there is a cluster of cases like this I think it is likely there is a viral cause," Professor Simon Taylor-Robinson, Hepatologist at Imperial College London, who was not involved in the study, commented. “A whole host of viruses can cause hepatitis – hepatitis A to E are well-known, and Epstein Barr virus (that causes glandular fever) can be another cause."
Complicating the matter, several viruses – including adenoviruses, which can on rare occasions cause liver inflammation – are circulating at the moment.
"It is not uncommon to have adenoviruses in springtime. And there are other viruses around too – COVID-19 has been associated with inflammation of many other body organs," Taylor-Robinson continued. "At the moment we don’t know what the cause is or if any of these viruses are implicated. It is also difficult to work out cause and effect because viruses can be common anyway so might be present but not necessarily the cause."
Though concerning, experts highlight the fact that the liver is very good at regenerating itself over time. Parents and carers should get in contact with a healthcare provider should they notice any symptoms of hepatitis in their children. In the meantime, health authorities and the WHO will continue to investigate.
“Hepatitis is unusual in children. In relation to viral hepatitis, infection in childhood very rarely causes clinical disease (this is true of most virus infections – the disease is often much worse if caught as an adult)," Prof Will Irving, Professor of Virology, University of Nottingham, told Science Media Centre.
“The current crop of cases of hepatitis in children under the age of 10 years is therefore very unusual. At present, a specific cause has not been identified, but investigations are ongoing to try and find the cause. These include looking for toxins in samples from the patients (toxicology) and also trying to identify any virus which might be responsible.”