Five children have died from unexplained hepatitis in the US and more than 100 cases have been spotted across 25 states, the CDC revealed today.
The agency’s deputy director for infectious diseases Dr Jay Butler revealed they were now probing whether exposure to animals — including pet dogs — could be behind the spate of cases.
It comes after officials in the UK — where more than 160 cases have been detected — also said they were looking into the link after finding a ‘high’ number of children with hepatitis had pet dogs or were exposed to them.
Butler said they were still looking into whether Covid or a previous Covid infection may have triggered the cases.
The children were about two years old on average, he said, and more than 90 percent were hospitalized. A total of 14 percent also needed a liver transplant.
The patients had also all fallen sick since October, or in the past seven months. No link has been identified with the Covid vaccine.
Scientists have been left puzzled over what is causing the illness — with the usual hepatitis A, B, C, D and E viruses excluded from laboratory test results.
The leading theory is that adenoviruses — which can trigger the common cold — could be behind the spate of illnesses.
But suggestions weakened immunity from lockdowns, pet dogs or a previous Covid infection are behind the cases are yet to be ruled out.
Ohio and North Dakota became the thirteenth and fourteenth states to report confirmed or suspected cases of the mysterious hepatitis illness yesterday
Health chiefs claim a ‘high’ number of the sickened children, who are aged 10 and under, come from families which own dogs or have had ‘dog exposures’ in the UK
Asked whether the cases in the U.S. could be linked to pet dogs, Dr Butler said: ‘The investigation of the persons under investigation in the U.S. does include questions about animal exposure as well.
‘We really are casting a broad net and keeping an open mind in terms of whether the adenovirus may affect an innocent bystander or whether there may be cofactors that are making the ad manifest in a way that has not been commonly seen before.
‘It is challenging because it is still a very rare occurrence.’
He said cases had been confirmed in the following states: Alabama, Arizona, California, Colorado, Delaware, Florida, Georgia, Idaho, Illinois, Indiana, Louisiana, Michigan, Minnesota, Missouri, North Carolina, North Dakota, Nebraska, New York, Ohio, Pennsylvania, Texas, Washington and Wisconsin.
It is still not clear what is triggering the condition, with experts warning it could take at least three months to find out.
Dr Nicole Saphier, a radiologist at the Memorial Sloan Kettering center in New Jersey, today told DailyMail.com it was possible that the cases were down to weakened immunity.
She said: ‘The last two years children have been shielded from every day pathogen exposure through masking, decreased social interactions and remote learning.
‘[As a result], it is possible that children being sheltered from the pandemic are now having more severe reactions to common pathogens like adenovirus.’
On Tuesday the World Health Organization declared at least 228 probable cases of hepatitis in children had been reported from 20 countries.
It said there were more than 50 other cases under investigation.
Most cases were from the UK, 145, and U.S., 20, they said, which have some of the strongest surveillance systems.
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.
Indonesia on Tuesday said three children had died from suspected hepatitis of unknown cause.
Children struck down with hepatitis in America have generally been less than 10 years old.
Those with the condition suffered with vomiting, diarrhea and jaundice — where the skin and whites of the eyes turn yellow —, the CDC said.
More than half also suffered a fever due to the condition.
Most children swabbed have tested positive for adenovirus, fueling theories that this could be behind the spate of illnesses.
But some are not convinced, pointing out that it is not uncommon to be infected with this virus.
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.
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 UKHSA 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.