Explained: Mysterious Hepatitis outbreak and sudden liver disease rise in kids
Health authorities in Europe and the US are racing to find out about the sudden outbreak of a liver disease in nearly 200 children. According to the World Health Organization (WHO), as many as 17 children have needed liver transplants as a result of the recent cases, while one has succumbed to the disease.
The European Centre for Disease Prevention and Control on Tuesday said around 190 unexplained cases of severe hepatitis have been reported in children around the world, including in the UK, the US and Israel.
Where has it been detected?
The first five cases were flagged in Scotland on March 31 by "astute clinicians, realising they were seeing something unusual", said Meera Chand, director of clinical and emerging infections at the UK Health Security Agency. The children did not have any of the five known hepatitis viruses, A, B, C, D and E, Chand said. Such cases are very rare as the Scottish doctors would normally see four to five unknown hepatitis cases in a year, news agency AFP reported quoting the doctor.
The UK has since reported a total of 114 cases, mostly in children under 10, the WHO said.
Since it has been identified in at least 12 countries worldwide, news agency AP reported.
Spain had the next highest number of cases with 13, followed by Israel with 12 and the US with nine, while small numbers have also been recorded in Denmark, Ireland, the Netherlands, Italy, Norway, France, Romania and Belgium.
Who has been affected?
Children aged from one month to 16 years old have had the mystery disease, but most cases have been aged under 10. Notably, the large majority were previously healthy.
What are the symptoms?
Before the children showed signs of severe hepatitis, they had symptoms that included jaundice, diarrhoea, vomiting and abdominal pain. Maria Buti, a pathologist in Barcelona and chair of the European Association for the Study of the Liver (EASL), told AFP that the "main concern" is the strain's severity.
Seventeen of the children -- 10 per cent of the 169 known cases -- had such severe hepatitis that they needed a liver transplant, she added.
However, it was not confirmed whether even more children had mild cases because their symptoms were not traceable.
What has been ruled out?
No common exposure seems to link the patients, the experts said, and the WHO ruled out international travel as a factor.
There was no link to paracetamol, overdoses of which can cause liver failure.
Any link to Covid vaccines has also been ruled out because most of the children were not old enough to be jabbed.
Causes for the unknown strain
Adenoviruses -- common viruses that cause a range of sicknesses like colds, bronchitis and diarrhoea but mostly do not lead to severe illness -- were detected in 74 of the cases, the WHO said.
Chand said adenovirus was found in 75 per cent of patients in the UK.
She said the "leading hypothesis" was a combination of a normal adenovirus along with another factor that was making it more severe.
Other possible causes for the unknown strain could be a combination of adenovirus and Covid, or related to previous Covid infection, Chand said.
Nineteen of the 169 recorded cases had both Covid and adenovirus, while 20 had just Covid.
Hepatitis is usually caused by one of several contagious hepatitis viruses that have not been found in the affected children. Sometimes the disease is mild and requires no specific treatment. But severe cases require hospitalisation and can lead to liver failure.