The World Health Organization has confirmed eight more countries have reported cases of mystery hepatitis in children.
It brings the total number of countries with cases to 20. Globally, 228 children have been sickened with an unusual form of liver disease and another 50 suspected cases are being probed.
One death has been confirmed but four more are suspected, and 18 children have required a liver transplant.
Most of the cases have been detected in Europe but there are others in the Americas, the Western Pacific, and Southeast Asia.
Scientists are bemused by the spate of cases because none of the affected children have tested positive for normal hepatitis-causing viruses.
Adenoviruses, which normally cause the common cold and stomach bugs are thought to be the culprit, despite rarely causing liver inflammation.
There are concerns lockdowns may have weakened children’s immunity to normally benign viruses and investigations are also looking at whether a mutated adenovirus or Covid are involved.
But UK scientists have admitted it could take at least three months until health chiefs know exactly what is behind the spate of cases.
WHO spokesman Tarik Jasarevic told reporters in Geneva today: ‘As of May 1, at least 228 probable cases were reported to WHO from 20 countries, with over 50 additional cases under investigation.’
Most of the cases have been detected in the UK (145) and US (20), which have some of the strongest surveillance systems.
It previously announced hepatitis cases of an ‘unknown origin’ had been confirmed in Ireland, Spain, France, Germany, Belgium, Italy, and the Netherlands, as well as Israel, Denmark, Norway, and Romania.
In its first update on the hepatitis outbreak since April 23, the WHO said cases have spread to eight more countries.
The agency did not reveal which countries had reported the extra cases but other health bodies revealed Austria, Germany, Poland, Japan, and Canada have detected cases, while Singapore is probing a possible case in a 10-month-old baby.
Yesterday Indonesia said three children had died from suspected hepatitis of unknown cause.
The 145 affected children in Britain, who have mainly been aged five and under, initially suffered from diarrhoea and nausea, followed by jaundice — yellowing of the skin and whites of eyes.
The WHO confirmed one death, although it did not reveal the location. One fatality in the US is being probed, along with the three in Indonesia.
UK health chiefs told MailOnline today that no hepatitis deaths have been logged in Britain.
The youngsters in Indonesia, aged two, eight and 11, suffered from a fever, jaundice, as well as abdominal pain, vomiting, diarrhoea and dark-coloured urine.
The country’s health chiefs suspect the cases were hepatitis but they are running tests to determine whether the usual A to E hepatitis viruses were behind them, or if their origin is unknown.
The WHO was first informed of the cases by health chiefs in Scotland on April 5, after they detected 10 cases in children under the age of 10, the earliest of which was dated back to January.
Dr Meera Chand, director of clinical and emerging infections at UKHSA, said parents may be concerned but the likelihood of their child developing hepatitis is ‘extremely low’.
‘However, we continue to remind parents to be alert to the signs of hepatitis – particularly jaundice, which is easiest to spot as a yellow tinge in the whites of the eyes – and contact your doctor if you are concerned,’ she said.
Dr Chand added: ‘Normal hygiene measures including thorough handwashing and making sure children wash their hands properly, help to reduce the spread of many common infections.
‘As always, children experiencing symptoms such as vomiting and diarrhoea should stay at home and not return to school or nursery until 48 hours after the symptoms have stopped.’