US health officials have sent out a nationwide alert warning doctors to be on the lookout for symptoms of unexplained hepatitis in children, following clusters of mysterious cases in the US and UK.
The Centers for Disease Control and Prevention is expanding its probe after dozens of young children developed acute hepatitis but did not have the hepatitis A, B or C viruses that usually cause it.
On alert Thursday, the CDC said it was working with counterparts in Europe to understand the cause of the infection, and urged doctors across the country to report potential cases.
The common cold virus known as adenovirus has been confirmed in many, but not all, European cases.
In the UK, researchers have speculated that children may have a weakened immune system due to rounds of COVID-19 pandemic lockdowns.
However, cases of hepatitis in children in the United States so far are all in Alabama, a state that has not followed the strictest epidemic restrictions, deepening the puzzle.
Clusters of mysterious hepatitis in children prompted the CDC to issue a national alert
On Thursday, UK health authorities said they had identified a total of 108 cases of hepatitis in children. In some cases, cases were so severe that children required a liver transplant.
What is hepatitis?
Hepatitis is inflammation of the liver usually caused by a viral infection or liver damage from drinking alcohol.
Short-term hepatitis often has no noticeable symptoms.
But if some do appear, they can include dark urine, pale gray stools, itchy skin, and yellowing of the eyes and skin.
They can also include muscle and joint pain, a high temperature, and feeling unusually sick and tired all the time.
When hepatitis is spread by a virus, it is usually caused by ingestion of food and drink contaminated with the feces of an infected person, blood-to-blood or sexual contact.
Additional cases have been reported in Denmark, Ireland, the Netherlands and Spain, according to the European Center for Disease Prevention and Control.
Hepatitis simply means inflammation of the liver, which can have causes ranging from viruses and toxins to alcohol abuse.
The US alert directs physicians to report any suspected cases of the disease that occur with an unknown source to local and state health departments.
Doctors also suggest adenovirus testing in young patients with symptoms, which include fever, fatigue, loss of appetite, nausea, vomiting, abdominal pain, dark urine, light-colored stools, joint pain, and jaundice.
The warning came after the CDC’s investigation with the Alabama Department of Public Health into a cohort of nine cases of hepatitis of unknown origin in previously healthy children ages 1 to 6.
The first such cases in the United States were identified in October 2021 at a children’s hospital in Alabama that received five young patients with severe liver injury — including some with acute liver failure — of unknown cause.
In these cases, children have tested positive for adenovirus, a common family of viruses that can cause respiratory and gastrointestinal symptoms, but are rarely fatal.
The most common forms of liver disease – hepatitis A, hepatitis B and hepatitis C were excluded.
A review of hospital records identified four additional cases, all of whom had liver injury and adenovirus infection.
Centers for Disease Control and Prevention expands investigation after dozens of children develop acute hepatitis
Laboratory tests found that some of these children had been infected with type 41 adenovirus, which causes severe infections in the gastrointestinal tract. The country did not find any new cases outside the original group.
The Centers for Disease Control and Prevention is working with state health departments to identify additional US cases.
While the leading theory is that the cases are caused by a specific type of adenovirus, health officials are considering other potential contributing factors as well.
Writing in Eurosurveillance, a team led by Public Health Scotland epidemiologist Dr Kimberly Marsh said more children could be ‘immuno-naïve’ to adenovirus strains due to the pandemic restrictions.
They wrote: “The main hypotheses center around the adenovirus – either a novel variant with a distinct clinical syndrome or a routinely circulating variant that more commonly affects young children who are immune-naive.
The latter scenario may be the result of limited social interaction during a pandemic.
Nine US children – all under the age of six – have developed severe cases of hepatitis since October. Adenovirus is the prime suspect in the outbreak (Pictured: Stock image of the virus)
Public Health Scotland first sounded the alarm about unusual cases of hepatitis in children on 6 April.
Jim McMenamin, Scotland’s director of public health, told Reuters that 14 cases had now been identified in Scotland, including another one under investigation this week.
Researchers increasingly believe adenovirus infection could be behind the cases, possibly “in coordination” with another virus, with 77 per cent of children in the UK testing positive for adenovirus, McMenamin said.
However, he said, other causes were not ruled out, including exposure to toxins, COVID-19, or a new pathogen, either in conjunction with adenovirus infection, or alone.
None of the cases in the UK or the US have been linked to the COVID-19 vaccine. Alabama health officials said none of the nine cases had any prior history of COVID-19.