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.
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. The disease has been reported in 25 states including Puerto Rico.
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 the animals.
The leading hypothesis is that adenoviruses — which can cause the common cold — are behind the illnesses across the country, with the majority of cases in the U.S. testing positive for this.
But Butler said the CDC was keeping an ‘open-mind’ and also investigating whether a previous Covid infection and weakened immunity due to lockdowns was a factor. No link has been detected to Covid vaccines, with most of the patients not yet eligible to receive them.
At least eight children have now died in the hepatitis outbreak globally, with three cases also now being probed in Indonesia. There are more than 300 cases globally, with most in the UK and US due to better surveillance.
CDC chiefs did not reveal where in the U.S. the five deaths from hepatitis were reported, but one fatality has already been announced in Wisconsin by the state’s health chiefs.
The hepatitis cases were reported to the CDC after it sent out a nationwide alert telling medics to keep an eye out for cases of the illness.
Butler said a total of 109 cases of mysterious hepatitis had been detected so far, and that most of these had ‘recovered fully’ following the illness.
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.
Doctors in South Dakota also say they have reported cases of hepatitis, although this was not included in the CDC’s list.
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.’
None of the children had tested positive for Covid or had a previous infection with the virus. Surveillance is now underway to find out if they had a previous undiagnosed infection with the virus.
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.’
Other countries that have reported cases include Austria, Germany, Poland, Japan and Canada.
Children struck down with the illness generally have fever, fatigue, loss of appetite, nausea, vomiting, abdominal pain, dark urine, light-colored stools, joint pain and jaundice.
Parents have been advised to keep an eye-out for any tell-tale symptoms, but also told that the likelihood of their child being struck down with the disease is ‘extremely low’.