“It is not yet clear whether there has been an increase in hepatitis cases, or an increase in awareness of hepatitis cases that are occurring at the expected rate but going undetected,” the official said. WHO in a statement. “While adenovirus is a possible hypothesis, investigations are ongoing for the causative agent.”
The clinical syndrome “among the identified cases is acute hepatitis (inflammation of the liver) with markedly elevated liver enzymes,” the statement said. Many cases have reported gastrointestinal symptoms such as abdominal pain, diarrhea, and vomiting “preceding the presentation of severe acute hepatitis”, as well as increased liver enzyme or alanine aminotransaminase levels. and jaundice.
Most reported cases had no fever, the WHO said, and common viruses that cause acute viral hepatitis – such as hepatitis A, B, C, D and E viruses – do not were detected in any of these cases.
Hepatitis is an inflammation of the liver, a vital organ that processes nutrients, filters the blood and helps fight infection. When the liver is inflamed or damaged, its function can be affected.
Most often, hepatitis is caused by a virus, and adenoviruses are a common type of virus that spreads from person to person and can cause a range of mild to more serious illnesses. But these viruses are only rarely reported as a cause of severe hepatitis in healthy people.
The WHO said the investigation into the cause should focus on factors such as “increased susceptibility in young children following a lower circulating level of adenovirus during the COVID-19 pandemic, the potential emergence of a new adenovirus, as well as SARS-CoV-2 co-infections.”
The majority of cases – 114 – have been reported in the UK. There have been 13 cases in Spain, 12 in Israel, nine in the United States and a smaller number of confirmed cases in Denmark, Ireland, the Netherlands, Italy, Norway, France, Romania and Belgium, according to the WHO.
On Thursday, the US Centers for Disease Control and Prevention (CDC) issued a health advisory that alerted healthcare providers and public health authorities to an investigation into acute cases of hepatitis of unknown cause. .
The CDC has recommended providers consider testing children with hepatitis for adenovirus when the cause is unknown, adding that testing whole blood — not just blood plasma — may be more sensitive.
CNN’s Jacqueline Howard and Jen Christensen contributed to this report.