A child in Ireland has become the latest casualty of a mystery hepatitis spot in more than 20 countries.
Health officials said a second child who was also being treated for the same illness has received a liver transplant.
The youngsters’ ages have not been revealed but Ireland’s Health Service Executive (HSE) said its cases have been under 12.
Since March, six children have been hospitalised with hepatitis in Ireland, which the HSE claimed ‘is more than would usually be expected over this period of time’.
The latest death is thought to bring the global fatality toll to nine, with five reported in the US and three in Indonesia.
There have been nearly 350 cases of ‘severe hepatitis of unknown origin’ in children recorded in 21 countries since April, with 163 in the UK.
At least 26 youngsters have required liver transplants, according to the latest World Health Organization (WHO) update last week.
Experts have warned the current cases may be the tip of the iceberg due to poor surveillance in some countries.
Scientists are puzzled as to what is causing the unusual illness, but the main theory is that it is triggered by a group of viruses that normally cause the common cold.
The HSE said none of the cases in Ireland were linked and they were not linked to any of the patients in the UK. None had Covid, either.
Ireland is working closely with the WHO and colleagues in the EU and Britain to identify the cause of the illnesses.
Parents are advised to go to their GP if their child develops symptoms of hepatitis, which include pale, grey-coloured stools, very dark urine, or a yellowing of the eyes and skin.
The common viruses that cause hepatitis: hepatitis viruses A, B, C, and E; have not been detected in any of the cases reported worldwide.
In its most recent update on May 9, the WHO said there had been 348 probable cases of hepatitis of unknown origin since the first was reported in Scotland in April.
All of the cases are among children aged 11 months to five years and ‘many’ tested positive for adenovirus.
The virus has not yet been identified in the liver tissue samples analysed ‘and therefore, could be a coincidental rather than a causal factor’, the WHO said.
In new guidance this week, the Centers for Disease Control and Prevention (CDC) in the US has told doctors treating children with hepatitis to take liver samples for analysis.
US STATES WITH CASES: The above map shows the 26 states that have confirmed or suspected hepatitis cases according to the CDC. Massachusetts and Hawaii became the 25th and 26th states to reveal they are probing suspected cases of the illness (yellow), with Puerto Rico also having reported at least one case
Three quarters of the UK’s hepatitis-stricken children have tested positive for adenoviruses, analysis suggests.
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 can’t rule out an old Covid infection being involved.
In a bizarre twist last week, health chiefs in the UK are also investigating whether ‘dog exposures’ are to blame.
The UK Health Security Agency (UKHSA) said last week that a ‘high’ number of the British children with hepatitis were from families which own dogs.
Officials did not explain how dogs could potentially be to blame, but they are known carriers of adenovirus strains.
However, health officials have ruled out the Covid vaccine as a possible cause because the majority of the ill British children haven’t been vaccinated due to their young age.
Hepatitis is usually rare in children, but experts have already spotted more cases in the UK since January than they would normally expect in a year.
Q&A: What is the mysterious global hepatitis outbreak and what is behind it?
What is hepatitis?
Hepatitis is inflammation of the liver that is usually caused by a viral infection or liver damage from drinking alcohol.
Some cases resolve themselves, with no ongoing issues, but a fraction can be deadly, forcing patients to need liver transplants to survive.
What are the symptoms?
People who have hepatitis generally have fatigue, loss of appetite, nausea, vomiting, abdominal pain, dark urine, light-colored stools and joint pain.
They may also suffer from jaundice — when the skin and whites of the eyes turn yellow.
Why are experts concerned?
Hepatitis is usually rare in children, but experts have already spotted more cases in the current outbreak than they would normally expect in a year.
Cases are of an ‘unknown origin’ and are also severe, according to the World Health Organization. It has caused up to two deaths and 18 liver transplants.
What are the top theories?
Experts say the cases may be linked to adenovirus, commonly associated with colds, but further research is ongoing.
This, in combination with Covid infections, could be causing the spike in cases.
The WHO reported adenovirus has been detected in at least 74 of the cases. At least 20 of the children tested positive for the coronavirus.
British experts tasked with investigating the spate of illnesses believe the endless cycle of lockdowns may have played a contributing role.
Restrictions may have weakened children’s immunity because of reduced social mixing, leaving them at heightened risk of adenovirus.
This means even ‘normal’ adenovirus could be causing the severe outcomes, because children are not responding to it how they did in the past.
Other scientists said it may have been the adenovirus that has acquired ‘unusual mutations’.
This would mean it could be more transmissible or better able to get around children’s natural immunity.
New Covid variant
UKHSA officials included ‘a new variant of SARS-CoV-2’ in their working hypotheses.
Covid has caused liver inflammation in very rare cases during the pandemic, although these have been across all ages rather than isolated in children.
The CDC has noted environmental triggers are still being probed as possible causes of the illnesses.
These could include pollution or exposure to particular drugs or toxins.