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  • A new report finds reported that nearly 200 children have developed acute hepatitis from an unknown cause.
  • The disease was so severe that children needed a liver transplant in some cases.
  • After analyzing the available data, experts say the cause remains unknown, but they are investigating if a type of adenovirus may be involved.

Unexplained cases of hepatitis in children have health officials across the globe puzzled and concerned.

The European Centre for Disease Prevention and Control reported that there are at least 191 known cases in the UK, Europe, the US, Canada, Israel, and Japan

The news comes after the UK Health Security Agency released a report on their investigation into the outbreak earlier this week. They reported that their leading hypothesis is that adenovirus infection is linked to the mysterious rise of severe hepatitis cases in children.

Earlier this month World Health Organization (WHO) issued a release about the state of the outbreak globally.

The WHO reported that the age of the children affected ranged from 1 month to 16 years. At least 17 of the children were so ill that they needed a liver transplant.

According to the report from the European Centre for Disease Prevention and Control, the children tended to have gastrointestinal distress including vomiting, diarrhea, and nausea before they developed jaundice, which is a sign of liver disease.

At least one child has died.

UK officials pointed out that an adenovirus infection may be just one part factor that has resulted in the hepatitis outbreak. Of the 111 confirmed hepatitis cases in the UK, 53 of the children were tested for adenovirus. Forty of these children tested positive for the disease.

“There may be a cofactor causing a normal adenovirus to produce a more severe clinical
presentation in young children, such as increased susceptibility due to reduced exposure during
the pandemic, prior SARS-CoV-2 or other infection, or a yet undiscovered coinfection or toxin,” the authors wrote.

They also pointed out there may be a new type of adenovirus that is causing severe symptoms.

Most of the children involved were under age 5. They presented with gastroenteritis symptoms, meaning the gastrointestinal tract was inflamed, before developing jaundice, which is a sign the liver isn’t functioning properly.

The WHO said in their earlier report that the adenovirus hypothesis is being investigated.

“It is not yet clear if there has been an increase in hepatitis cases or an increase in awareness of hepatitis cases that occur at the expected rate but go undetected. While adenovirus is a possible hypothesis, investigations are ongoing for the causative agent,” WHO officials wrote.

Earlier this month, the Centers for Disease Control and Prevention (CDC) sent out a nationwide alert for physicians due to the outbreak. They issued a Health Alert Network (HAN) Health Advisory for healthcare providers asking them to be on the lookout for any symptoms of this disease and to report any similar hepatitis cases.

Two cases in Alabama were severe enough for children to require a liver transplant, although no deaths have been reported so far in the U.S.

Michelle M. Kelly, PhD, CRNP, Associate Professor at M. Louise Fitzpatrick College of Nursing, said in an interview last week that the hepatitis experienced by the children in Alabama doesn’t appear to be caused by the viruses typically associated with hepatitis.

“Logic would then lead us to think that the cause is either another type of exposure, a virus not yet identified, or an exposure to a substance that is causing the liver impairment,” she said.

According to U.K. officials, potential causes being actively investigated include COVID-19, “other infections,” and environmental causes.

The European Centre for Disease Control confirmed that detailed information collected by questionnaire regarding the children’s food, drink, and personal habits “failed to identify any common exposure.”

According to Alabama health officials, none of the children in that state tested positive for any variety of hepatitis virus or had other typical risk factors for the disease.

“These children presented to providers in different areas of Alabama with symptoms of a gastrointestinal illness and varying degrees of liver injury, including liver failure,” Alabama Public Health (APH) said in a statement.

In the HAN advisory, the CDC asked physicians to check for an adenovirus infection if a patient has symptoms similar to those found in the cases in Alabama.

Kelly said adenovirus infections are very common and typically result in mild flu-like illnesses that in healthy children do not progress to hepatitis.

“It is important to know that having adenovirus concurrently with this unexplained hepatitis does not mean that the hepatitis was caused by the adenovirus,” she said, noting that adenovirus has been previously linked to hepatitis – but involved people who were already immunocompromised.

Kelly emphasized that any link will need to be explored by additional testing of tissue samples from the patients involved.

Ilan Shapiro, MD, FAAP, chief health correspondent, and medical affairs officer at AltaMed Health Services, told Healthline that hepatitis is liver inflammation.

“Common causes of liver inflammation are alcohol, medications, nonalcoholic fatty liver disease where weight is involved, and viruses that attack the liver,” he said.

Shapiro emphasized that liver disease can severely affect health throughout the body.

“When the liver cannot function properly, cirrhosis and cancer can develop – when the liver gets inflamed, the whole body suffers,” he added.

Alexander Weymann, MD, a pediatric gastroenterologist and hepatologist and director of the Liver Center, and medical director of Liver Transplantation at Nationwide Children’s Hospital, said that people who develop acute hepatitis could often recover.

“If the liver recovers spontaneously, then no long-term health consequences are to be expected,” he said. “The exception would be an acute hepatitis that is so severe as to cause acute liver failure.”

According to Weymann, acute liver failure can lead to death or the need for liver transplantation.

“However, it is important to note that these cases now reported by the WHO are cases of acute hepatitis that do not lead to chronic liver disease,” he said. “Although some have caused acute liver failure and even gone on to liver transplantation, and for which no specific treatment, such as an antiviral drug, is available.”

According to APH, adenoviruses may spread from a person to others in several ways:

  • Close personal contact
  • Through the air by coughing and sneezing
  • Touching an infected surface and then touching the mouth or eyes
  • Contact with stool, as may occur during diaper changing

The agency warned that adenoviruses are often resistant to common disinfectants and can remain infectious for long periods on surfaces and objects.

Basic steps APH recommends to protect ourselves, and our children include frequent handwashing, avoiding touching eyes, nose, or mouth with unwashed hands, and avoiding close contact with anyone who is sick.

There has been an outbreak of unexplained hepatitis affecting children in Europe and the U.S.

After analyzing the available data, experts say the cause remains unknown, but they suspect a type of adenovirus may be involved.

They also say any link to this virus will need to be confirmed by further testing tissue samples from the affected children.