New Delhi: At least one child has died after falling ill from a mysterious outbreak of acute hepatitis that has infected children in 11 European countries, the World Health Organization (WHO) has confirmed.
At least 169 cases of acute hepatitis of unknown origin have been reported from 11 countries in Europe — with the highest number of cases reported from the UK — among children aged between one month and 16 years. The WHO added that 17 children have so far required liver transplants. However, the WHO hasn’t clarified where the death took place.
According to the WHO, the UK had notified it on 5 April about 10 cases of “severe acute hepatitis of unknown aetiology in previously healthy young children (age range: 11 months to five-year-old) across central Scotland. Of these 10 cases, nine had onset of symptoms in March 2022 while one case had an onset of symptoms in January 2022.” By 8 April, a total of 74 cases had been identified in the UK after further investigations.
As of 21 April, as many as 114 cases had been reported in the UK, 13 in Spain, 12 in Israel, nine in the US, six in Denmark, five in Ireland, four each in The Netherlands and Italy, two each in Norway and France, and one each in Romania and Belgium.
Also read: Liver disease rose 10-15% under Covid lockdowns as Indians drank more, worked out less
What is hepatitis?
Hepatitis is an inflammation of the liver caused by a variety of infectious viruses and non-infectious agents (such as alcohol) leading to a range of health problems, some of which can be fatal.
There are five main strains of the hepatitis virus, referred to as types A, B, C, D, and E. While they all cause liver disease, they differ in how they spread, the severity of the illness they cause and the ways they can be prevented.
However, for the current outbreak, experts have not been able to identify the virus or its origin. According to the WHO, the common viruses that cause acute viral hepatitis have not been detected in any of these cases.
However, adenovirus has been detected in at least 74 cases. At least 18 have been identified as adenovirus F type 41.
Adenoviruses are common pathogens that usually cause mild infections. They spread from person to person and most commonly cause respiratory illness, but depending on the type, can also cause other illnesses such as gastroenteritis, conjunctivitis, and bladder infection.
There are more than 50 types of immunologically distinct adenoviruses that can cause infections in humans. Adenovirus type 41 typically presents as diarrhoea, vomiting, and fever, often accompanied by respiratory symptoms. While there have been case reports of hepatitis in immunocompromised children with adenovirus infection, adenovirus type 41 is not known to be a cause of hepatitis in otherwise healthy children.
The clinical syndrome among identified cases is acute hepatitis (liver inflammation) with markedly elevated liver enzymes. Many cases reported gastrointestinal symptoms including abdominal pain, diarrhoea, and vomiting before presenting with severe acute hepatitis, as well as increased levels of liver enzymes and jaundice. Most cases did not have a fever.
The United Kingdom, where the majority of cases have been reported to date, has also observed a significant increase in adenovirus infections in the community — particularly detected in faecal samples in children — following low levels of circulation earlier in the Covid-19 pandemic. The Netherlands also reported concurrent increasing community adenovirus circulation.
While the WHO acknowledged that the increased enhanced testing for adenovirus may have led to identifying more cases that are usually not detected, in its latest technical briefing the UK Health Security Agency (UKHSA) suggested that reduced exposure to common viruses among toddlers due to the pandemic may be resulting in severe clinical symptoms in young children.
“Alternatively, there may have been an emergence of a novel adenovirus strain with altered characteristics,” according to the UKHSA briefing.
Further investigations are ongoing in countries that have identified cases and include more detailed clinical and exposure histories, toxicology testing, and additional virological/ microbiological tests, according to the WHO.
Also read: How Corbevax and Covovax, the two vaccines newly approved in India, fight Covid
Unanswered questions
While adenovirus is currently one hypothesis as the underlying cause of the outbreak, it does not fully explain the severity of the clinical picture. Infection with adenovirus type 41 has not previously been linked to such symptoms.
The WHO recommends that testing of blood, serum, urine, stool, and respiratory samples, as well as liver biopsy samples (when available), should be undertaken.
Currently, the WHO does not recommend any restriction on travel or trade with the UK, or any other country where cases have been identified.
(Edited by Manoj Ramachandran)
Also read: Raw meat comes with health dangers you must consider before taking up ‘wolverine diet’