Health officials across the world are investigating a recent and worrying spike in cases of hepatitis in children, but still do not have the answer.
A number of hypotheses are being explored, and one of these is the possibility that lockdown and social distancing might be behind the cluster of cases.
Dr Tassos Grammatikopoulos is one of the country's leading paediatric liver specialists and at Kings College Hospital where he works they have seen a rise in cases this year.
He said: "The most recent lockdown and the pandemic has probably played a part in this because children have not been exposed to common pathogens to common infections, like they would have had we all been out and about venturing in the community.
Dr Tassos Grammatikopoulos is one of the country's leading pediatric liver specialists
"So I think that probably plays a part in this. But also there are a lot of other factors that we're looking at very carefully with other agencies in the country trying to establish exactly what's going on."
Possible other explanation
Without strong evidence for any another cause it is an obvious link to explore: a worldwide lockdown followed by a sudden rise in hepatitis cases in young children.
But there could be another explanation.
A total of 114 cases have been reported in Britain, since the first cases were identified in Scotland less than four weeks ago. Ten of these children have needed a liver transplant.
Officials say some 77% of these children have tested positive for adenovirus. This is the virus that usually causes cold or flu-like symptoms. But when the virus attacks a weakened or compromised immune system it can lead to hepatitis.
Another hypotheses is that the adenovirus has mutated.
COVID vaccine ruled out
UK health officials have ruled out the COVID vaccine as a possible cause. They also said none of the cases in children aged 10 and under in Britain had been vaccinated
Hepatitis is not uncommon in children, especially at this time of year. But it is the surge in numbers and the really serious cases that worries health officials.
The UK Health Security Agency (UKHSA) said they would normally expect to see cases like this over a whole year and not in the space of a few months.
The good news is that there have not been any recent transplants and most children do make a full recovery, more than half according to the most recent data.
Parents are being urged to stay vigilant for the signs of suspected hepatitis, including jaundice, and if they are worried about their children's health to contact their doctor.
