A mysterious liver disease that has infected children in a dozen countries around the world has reached Asia, with a case reported in Japan.
The case in Japan of acute hepatitis – or inflammation of the liver – of unknown origin was flagged by local authorities on 21 April in a child who had tested negative for adenovirus – a possible cause being investigated worldwide – and Covid-19.
The patient had not had a liver transplant, the health ministry said on Monday, without giving further details.
Canada’s Public Health Agency said on Tuesday it was investigating reports of severe acute hepatitis of unknown origin in young children. It did not reveal the number of cases or their location.
So far across the world, 190 mystery cases of acute hepatitis in children have been reported, with 140 of them in Europe, mostly in the UK (110 cases). Further cases have been found in Israel and in the United States. Seventeen children became so sick they needed liver transplants.
The US Centers for Disease Control and Prevention said in a nationwide health alert last week that the first US cases were identified in October in Alabama. The first UK cases were recorded in January.
On Saturday, the World Health Organization (WHO) said at least one death had been reported in connection the outbreak. The UN health agency said the cases were reported in children aged between one month and 16 years. The WHO did not say in which country the death occurred.
Hepatitis is usually caused by one of several contagious hepatitis viruses, but these have not been found in the affected children. Jaundice, diarrhoea and abdominal pain are among reported symptoms.
One theory being investigated by the UK Health Security Agency is that a lack of exposure to the common adenovirus – which usually causes stomach upsets and colds – during the coronavirus pandemic has led to more severe illness among children. Of 53 cases tested in the UK, 40 (75%) showed signs of adenovirus infection.
Public Health Scotland’s director, Jim McMenamin, told Reuters that work was under way to understand if an adenovirus has mutated to cause more severe disease, or if it could be causing the problems “in tandem” with another virus, including possibly Sars-CoV-2, the virus that causes Covid-19.
UK officials said there was “no link” between the cases and the Covid-19 vaccine, because none of the children affected by hepatitis had received a jab.
Andrea Ammon, director at the European Centre for Disease Prevention and Control in Stockholm, said: “So far there is no connection between the cases and no association to travel.”
The disease appeared in previously healthy children, Ammon said.