Public health officials in the United States and the United Kingdom are investigating a number of unusual cases of serious hepatitis in young children, the cause or causes of which are currently unknown.
Evidence from the U.K. and from Alabama — where nine cases have been recorded since last fall — points to the possible involvement of an adenovirus. Adenoviruses generally attack the respiratory tract, causing cold-like illnesses. But they have been linked to bladder inflammation and infection, and occasionally to hepatitis, though rarely in children who are not immunocompromised.
In a statement issued late Thursday, the Centers for Disease Control and Prevention said it is working with Alabama on its investigation into the cases, and is working with other state health departments to see if there are other cases elsewhere. In an alert to doctors the Alabama public health department issued in early February, it mentioned being aware of a case in another state, but it did not give details.
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“CDC is aware of and working with the Alabama Department of Public Health to investigate nine cases of hepatitis in children — ranging in age from 1 to 6 years old — who also tested positive for adenovirus since October 2021,” Kristen Nordlund, a spokeswoman for the agency, said in a statement.
“CDC is working with state health departments to see if there are additional U.S. cases, and what may be causing these cases. At this time adenovirus may be the cause for these, but investigators are still learning more — including ruling out the more common causes of hepatitis,” she said.
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Karen Landers, district medical officer for the Alabama Department of Public Health, said the cases were found in various parts of the state, and investigations to date have not found links among the children. Investigators in the U.K. have also not found links among the cases there.
“It is not common to see children with severe hepatitis,” Landers, who has been a pediatrician for 45 years, told STAT in an interview. “Seeing children with severe [hepatitis] in the absence of severe underlying health problems is very rare. That’s what really stood out to us in the state of Alabama.”
There are a range of adenoviruses that can infect people. Genetic sequencing is underway to try to identify if one or multiple types of adenoviruses are implicated. To date, five of the children have tested positive for Type 41, Landers said.
As word of the condition spreads, it is possible additional cases will be found. The newspaper El País reported Wednesday that Spain had detected three cases, all in children between the ages of 2 and 7. One of the children required a liver transplant, the newspaper said.
As in the U.K., the children in Alabama were quite sick, said Helena Gutierrez, medical director of the pediatric liver transplant program at the University of Alabama at Birmingham. “We have seen a full spectrum of cases from severe hepatitis to acute liver failure,” she told STAT in an email.
Nirav Shah, director of the Maine Center for Disease Control and president of the Association of State and Territorial Health Officers, said the organization knows of the cases in the U.K., but had not been made aware there were similar cases in this country. “We have reached out to the U.S. CDC to learn more as well as to discuss how states can undertake surveillance for such cases,” he said.
In the U.K., where roughly 75 cases have been reported from England and Scotland, a small number of the children have had or may require liver transplants.
A number of the affected children in the U.K. have tested positive for adenoviruses and for SARS-CoV-2, the virus that causes Covid-19. But the former appears to be the leading suspect, according to a scientific article on the Scottish cases that was published Thursday in the online journal Eurosurveillance.
Still, even if the cause is adenovirus infection, there may be a link to the pandemic, the authors suggested, noting that young children — many of the cases are under the age of 5 — who haven’t been exposed to the normal array of germs during the pandemic may have been rendered more vulnerable when masks came off and social distancing measures were lifted.
“At the time of publication, the leading hypotheses center around adenovirus — either a new variant with a distinct clinical syndrome or a routinely circulating variant that is more severely impacting younger children who are immunologically naïve,” wrote the authors, from Public Health Scotland, the Royal Hospital for Children in Glasgow, and the University of Glasgow Centre for Virus Research.
“The latter scenario may be the result of restricted social mixing during the Covid-19 pandemic,” they said. Five of the 13 children described in the article tested positive for adenovirus infection.
Hepatitis — inflammation of the liver — is a condition that can be caused by a number of factors, though often viral infections are the cause. A number of hepatitis viruses — A, B, C, D and E — are common causes of hepatitis, but they have been ruled out in these cases.
The European Centre for Disease Prevention and Control issued an alert on Tuesday urging doctors to be on the lookout for, and to report, cases of acute hepatitis in children aged 16 and younger where testing rules out infection with hepatitis viruses A, B, C, D or E.