Eight other countries have reported cases of mysterious childhood hepatitis in the past week, the World Health Organization has confirmed.
It brings the total number of countries with cases to 20. Worldwide, 228 children have fallen ill with an unusual form of the liver disease and a further 50 suspected cases are under investigation.
One death has been confirmed, but four more are suspected and 18 children have had to undergo a liver transplant.
Experts say the current count could be the “tip of the iceberg,” with many countries only now stepping up surveillance for the unusual complication.
Most of the cases so far have been discovered in Europe, but there are other cases in the Americas, the Western Pacific and Southeast Asia as well.
Scientists are surprised at the surge in cases because none of the affected children have tested positive for normal hepatitis-causing viruses.
Adenoviruses — which normally cause colds and stomach ulcers — are thought to be the culprit, despite rarely causing liver inflammation.
There are concerns that lockdowns have weakened children’s immunity against normally benign viruses and studies are also looking to see whether a mutated adenovirus or Covid is involved.
But British scientists have admitted it could be at least three months before health leaders know exactly what’s behind the wave of cases.

The World Health Organization has been notified of at least 228 children suffering from liver inflammation at the beginning of the month, with another 50 under investigation

Covid lockdowns may be behind mysterious wave of childhood hepatitis cases as they reduced social mixing and weakened their immunity, experts say

WHO spokesman Tarik Jasarevic told reporters in Geneva today: “As of May 1, at least 228 possible cases were reported to WHO from 20 countries, with more than 50 under investigation.”
Most cases have been detected in the UK (145) and US (20), which have some of the strongest surveillance systems.
It previously announced that hepatitis cases of “unknown origin” had been confirmed in Ireland, Spain, France, Germany, Belgium, Italy and the Netherlands, as well as in 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 has not revealed which countries reported the additional cases, but other health authorities revealed that Austria, Germany, Poland, Japan and Canada have detected cases, while Singapore is investigating a possible case in a 10-month-old baby.
And Indonesia said yesterday that three children had died of suspected hepatitis of unknown cause.
The 145 affected children in Britain, mainly aged five and under, initially suffered from diarrhea and nausea, followed by jaundice – yellowing of the skin and whites of the eyes.
The WHO confirmed one death, but did not disclose the location. One dead in the US is under investigation, along with the three in Indonesia.
British health chiefs told MailOnline today that no deaths from hepatitis have been recorded in Britain.
The young people in Indonesia aged two, eight and eleven had fever, jaundice, but also abdominal pain, vomiting, diarrhea and dark-colored urine.
The country’s health chiefs suspect the cases were hepatitis, but they are conducting tests to determine whether the common A to E hepatitis viruses were behind them, or whether their origins are unknown.
The WHO was first notified of the cases on April 5 by health chiefs in Scotland after discovering 10 cases in children under 10, the earliest dating back to January.
This was more than the average of seven to eight non-A to E hepatitis cases that Scotland usually records over the course of a year.
dr. Meera Chand, director of clinical and emerging infections at UKHSA, said parents may be concerned but the chances of their child developing hepatitis are ‘extremely low’.
“However, we continue to remind parents to be alert for the signs of hepatitis — particularly jaundice, which is most easily recognized as a yellow tinge in the whites of the eyes — and talk to your doctor if you’re concerned.” ‘, she said.
dr. Chand added: ‘Normal hygiene measures, including thorough hand washing and ensuring that children wash their hands properly, help reduce the spread of common infections.
“As always, children with symptoms such as vomiting and diarrhea should stay home and not return to school or daycare for 48 hours after the symptoms have resolved.”
Hepatitis is usually rare in children, but experts have already noticed more cases in the UK since January than they would normally expect in a year.
Scientists have previously suggested that cases could be just the “tip of the iceberg,” more likely to be there than has been noted so far.
Professor Alastair Sutcliffe, a leading pediatrician at University College London, said MailOnline health chiefs may not know the cause until later this summer.
He said: “With modern methods, computer science, advanced computers, real-time PCR and whole genome screening, I would think that finding the cause with reasonable confidence would take three months.”
Professor Sutcliffe said discovering the cause could be delayed by red tape across international borders, with difficulties in transporting biomaterials between countries.
Parental consent, data protection and laws regulating human tissue use in the UK could all delay research, he said.
Searching for an unknown cause is especially difficult because cases can have multiple factors that are not consistent for all diseases.
UK health officials have ruled out the Covid vaccine as a possible cause, and none of the sick UK children have been vaccinated due to their young age.
An official from the European Center for Disease Prevention and Control (ECDC) said the disease was “quite rare” but rated the risk to children as “high” because of its potential impact.
The risk to European children cannot be accurately assessed, as the evidence for human transmission was unclear and cases in the European Union “were sporadic with an unclear trend,” it said.
But given the unknown causes of the disease and the potential severity of the disease caused, the ECDC said the outbreak “presents a worrying public health event.”