Children’s hepatitis cases ‘have peaked’ as doctors study genetic link to disease
The mystery outbreak of hepatitis among children has peaked, experts believe, but those affected will have their DNA sequenced to find out if there is a genetic link to the condition.
Since January, 176 children have been diagnosed with unexplained acute hepatitis in Britain, with 11 requiring a liver transplant.
Doctors and scientists are still baffled about what is causing the condition, but suspect that some children may be having an unexpected reaction to an adenovirus, a common infection which can cause colds, sore throats, pneumonia and diarrhoea.
More than 70 per cent of children diagnosed with the condition were also found to have had an adenovirus infection, although experts are unsure what is the current background rate in the wider population.
Link to dogs ruled out
Fears that children could be picking up an infection from dogs was ruled out on Thursday by the UK Health Security Agency, and experts also no longer think that a coronavirus infection is directly triggering the condition.
Will Irving, a professor of virology at the University of Nottingham, said adenovirus was the “leading contender” but there had been no geographical clustering of cases, as might be expected with an infectious illness.
“If it is an infection in which many many children and adults are being infected, but the vast majority are not getting hepatitis, it begs the question what is special about these children?” he said.
Calum Semple, a professor in child health and outbreak medicine at the University of Liverpool, said that work was being done to sequence the genomes of affected children and their parents to see if they shared any genetic similarities.
“This could well be a very common infection by one virus or more and the vast majority of us don’t even know we’ve had it and there might be a subtle genetic predisposition that means some children get severe disease.
He added: “There has been nothing to point to Sars-Cov-2 being associated with this illness, far less being a cause. There is a stronger association with adenovirus and associated virus, which remain under investigation.”
About 20 children a year usually develop acute hepatitis, but figures for 2022 are already eight times higher. The majority of cases are in under-fives, which is also unusual, with diagnoses usually spread out through all age groups.
‘Post-lockdown surge is over’
The increase came alongside a surge in viruses as Britain emerged from social distancing and mask-wearing restrictions, but experts now believe that the surge is over.
“It does raise the possibility that what is happening more is simply more of what was happening before, if it is circulating at much higher levels and causing more causes,” said Prof Irving.
Blood tests have shown that where adenovirus is present is a specific variant known as adenovirus 41. Scientists are now studying the genome to find out if it has mutated from the usual sequence and also sampling livers which have been removed to see if the virus is present.
‘A bit of a wait and see’
Experts said it now appeared that cases had slowed down, which might be because of lower levels of viruses in circulation as Britain moves towards summer, when infections are traditionally lower.
Dr Tassos Grammatikopoulos, a consultant in paediatric hepatology at King’s College Hospital, said: “We seem to have passed the peak. Although we do still get some cases identified in the UK, we do seem to be on the downward trend.”
Deirdre Kelly, a professor of paediatric hepatology at the University of Birmingham, added: “Things do tend to improve in the summer in the warmth. I think it’s a bit of a wait and see.”
