Five healthy children have died in the unexplained hepatitis outbreak and more than 100 cases have been spotted leading to 15 liver transplants, the CDC revealed today.
The agency’s deputy director for infectious diseases Dr Jay Butler announced the grim tally in a press conference Friday, adding that the children were about two years old on average and had all fallen sick since October.
More than nine in ten patients had been hospitalized, he said, and all had previously been healthy and were not suffering from any underlying conditions.
It is not clear what is triggering the spate of illnesses, but CDC chiefs are now probing whether exposure to animals — including pet dogs — could be behind the cases.
Health chiefs in the UK — which has recorded more than 160 cases — said earlier today they were also looking into a link with canines after finding a ‘high’ number of children with hepatitis lived in families that had pet dogs or were exposed to dogs before falling sick.
The leading hypothesis is that adenoviruses — which can cause the common cold — are behind the illnesses across the country. But Butler said the CDC was also investigating whether a previous Covid infection and weakened immunity due to lockdowns was a factor.
No link has been detected with Covid vaccines, with most of the patients not yet eligible to receive them.
A total of 25 states, including Puerto Rico, have recorded cases of the mysterious hepatitis, the CDC revealed today. They are marked out above. It is not clear what is causing the outbreak but scientists are now investigating whether exposure to animals including pet dogs may be behind the illness
Dr Jay Butler, the agency’s deputy director for infectious diseases, revealed the grim tally at a conference today. It takes the global total to at least seven deaths, with three also under investigation in Indonesia
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
CDC chiefs did not reveal where in the U.S. the five deaths from hepatitis were reported, but one fatality has already been reported in Wisconsin.
It takes the global tally of fatalities from unexplained hepatitis to at least eight, after Indonesia said it was probing three child deaths from unexplained hepatitis.
More than 300 cases have been detected globally, with most cases reported in the UK and U.S. which both have stronger surveillance systems.
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.
Butler said the CDC had detected 109 cases of hepatitis so far, but that as these were probed some may not ‘wind up being part of the current investigation’.
He said cases had been reported 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, Tennessee, Texas, Washington and Wisconsin.
Puerto Rico also reported at least one case of hepatitis, the CDC said.
The agency would not reveal how many cases were in each state due to ‘confidentiality issues’.
Previously Alabama has declared the most cases out of any U.S. state, with nine reported.
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.’
Asked what the leading theory was behind what was triggering the cases, he said: ‘Because of the link to adenovirus I would call that top of the list of viruses of interest.
‘But we don’t know if it is adenovirus itself, immune reaction to this particular strain, or if there is an infectious or environmental co-factor that may be contributing as well.
‘At this point we have those hypotheses, but I think we are seriously considering whether or not this may be something that has happened at a low level for a number of years and we haven’t documented it.’
Dr Umesh Parashar, the chief of gastric viruses at the CDC who also attended the conference, warned surveillance of adenovirus cases was poor in the U.S.
But he said there had been no more cases of the virus than expected so far, with cases decreasing over the last three years due to efforts to stop the spread of Covid.
Butler added that there had not been a significant rise in liver transplants in the country.
Parashar said: ‘We are looking at this in a broad way.
‘If there is something about the host and lack of exposure previously or a previous Covid exposure as mentioned, or also if this was due to a particularly large season because of mitigations over the past two years [we will look into it].
‘It is also possible there might be some change in the virus itself.
‘We will only know that after some of the whole genome studies are completed and can put these strains against the template of background strains.
‘It is also a possibility that adenovirus is not a cause of this outbreak and we are certainly keeping an open mind to that and looking at environmental exposures or other viral pathogens.’
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.