A child in Ireland has become the latest victim of a mysterious outbreak of hepatitis in more than 20 countries.

Health officials said a second child who was also being treated for the same condition had received a liver transplant.

The youngsters’ ages were not revealed, but Ireland’s Health Service Executive (HSE) said their cases were under 12.

Since March, six children have been hospitalized with hepatitis in Ireland, which the HSE says “is more than you would usually expect over this period”.

The latest fatality is believed to bring the global death toll to nine, with five reported in the United States and three in Indonesia.

There have been nearly 350 cases of ‘severe hepatitis of unknown origin’ in children recorded in 21 countries since April, including 163 in the UK.

At least 26 young people have needed liver transplants, according to the latest update from the World Health Organization (WHO) last week.

Experts have warned that the current cases may just be the tip of the iceberg due to poor surveillance in some countries.

Scientists are puzzled as to the cause of this unusual disease, 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 see their GP if their child develops symptoms of hepatitis, including pale gray stools, very dark urine or yellowing of the eyes and skin.

Common viruses that cause hepatitis: hepatitis A, B, C and E viruses; have not been detected in any of the reported cases worldwide.

In its latest 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 in children aged 11 months to five years and ‘many’ have tested positive for the adenovirus.

The virus has not yet been identified in the analyzed liver tissue samples “and therefore could be a coincidence rather than a causative factor”, the WHO said.

In new guidelines this week, the Centers for Disease Control and Prevention (CDC) in the United States told doctors treating children with hepatitis to take liver samples for testing.

According to an analysis, three-quarters of children with hepatitis in the UK have tested positive for adenoviruses.

Scientists are investigating whether a mutated strain of adenovirus has evolved to become more severe, or whether a lack of social mixing during the pandemic has weakened children’s immunity. They cannot rule out that an old Covid infection is involved.

In a bizarre twist last week, UK health chiefs are also investigating whether ‘dog exposures’ are to blame.

The UK Health Safety Agency (UKHSA) said last week that a “high” number of UK children with hepatitis come from families with dogs.

Officials have not explained how the dogs could potentially be to blame, but they are known carriers of strains of adenovirus.

However, health officials have ruled out the Covid vaccine as a possible cause because the majority of sick British children have not been vaccinated due to their young age.

Hepatitis is generally rare in children, but experts have already spotted more cases in the UK since January than they would normally expect in a year.