Another 20 British children have fallen sick with hepatitis of unknown origin as the mysterious outbreak continues.
Health officials announced the new cases today, bringing the cumulative UK total to 222 since the first was spotted in January.
Of the confirmed patients, 158 were in England, 31 in Scotland, 17 in Wales and 16 in Northern Ireland.
They are predominantly in children under five — but a small number of children aged over 10 have also been struck down.
Scientists are still puzzled by what is causing the life-threatening liver disease, with weakened immunity to the common cold because of lockdowns still thought to be one of the chief culprits.
The complication has been spotted in hundreds of children in Europe, the US, South America, Middle East and Asia. At least 12 youngsters have died and dozens needed liver transplants. No children have died in the UK.
The UK Health Security Agency (UKHSA) said it is still investigating to find out what is behind the mysterious outbreak — with the usual hepatitis A, B, C, D and E viruses excluded from laboratory test results.
Scientists are still puzzled about what is causing the illness, which has been spotted in the US, Western Europe and a handful of other countries. Globally, at least 12 youngsters have died and dozens needed liver transplants
The main theory is that the spate of hepatitis cases are being triggered by a group of viruses that normally cause the common cold, known as adenoviruses.
Scientists are probing whether a mutated strain of adenovirus has evolved to become more severe, or if a lack of social mixing during the pandemic weakened children’s immunity.
They also have not been able to rule out an old Covid infection being involved.
UKHSA officials said there is no evidence linking the outbreak to the Covid vaccine as most cases have been in children under five years old, who have not been jabbed.
New cases appear to be slowing, with the 20 recorded in the nine days up to May 25 down 41 per cent on the 34 recorded in the six days up to May 16.
Dr Tassos Grammatikopoulos, a consultant at King’s College Hospital in London who has treated some of the sick children, last week said the UK ‘seems to be passed the peak’ of the outbreak.
Dr Renu Bindra, senior medical advisor at UKHSA, said: ‘Our investigations continue to suggest an association with adenovirus, and we are exploring this link, along with other possible contributing factors including prior infections such as Covid.
‘We are working with other countries who are also seeing new cases to share information and learn more about these infections.’
She added: ‘The likelihood of children developing hepatitis remains extremely low.
‘Maintaining normal hygiene measures, including making sure children regularly wash their hands properly, helps to reduce the spread of many common infections, including adenovirus.
‘We continue to remind everyone to be alert to the signs of hepatitis – particularly jaundice, look for a yellow tinge in the whites of the eyes – and contact your doctor if you are concerned.’
Symptoms of the complication normally start with diarrhoea or sickness. It then can cause the skin and eyes to turn yellow.
The US has recorded 216 cases across 37 states, with Mississippi and Utah the latest to be added to the growing list.
No new deaths or liver transplants were reported over the last seven days, the Centers for Disease Control and Prevention (CDC) revealed in their weekly update with the totals remaining at 14 and six respectively.
The agency has not revealed where the fatalities occurred due to ‘confidentiality issues’, but at least one was registered in Wisconsin health chiefs in the state say.
Globally, the UK has now recorded the most fatalities and suspected cases out of any nation — although this may be because of stronger surveillance than other nations.
Top experts fear health chiefs won’t understand what’s behind the peculiar pattern — which has been sickened at least 520 children worldwide since March — for months.
While mild liver inflammation is not uncommon in children, severe illness as seen in these cases is.
Dr Jason Kindrachuk, an assistant professor in medical microbiology and infectious diseases at the University of Manitoba, Canada, said experts are continuing to investigate the outbreak across the globe.
He told The Guardian: ‘The playing field is changing on an hour-to-hour basis. Inch by inch, we’re starting to figure out what this problem is.
‘But I don’t think we have all those pieces of the puzzle yet to say “Ok, this is what we think is going on”.’
The US and Indonesia have both five deaths in the outbreak, while Palestine and Israel have registered one each.