Until April 21, the World Health Organization ( WHO) has recorded a total of 169 cases in 11 countries of acute hepatitis of unknown origin in children ; some 17 children (approximately 10%) have required a liver transplant and at least one death has been reported in the UK .
According to information published by the United Nations international health organization, the cases are between 1 month and 16 years of age. Cases have been reported in: United Kingdom (114), Spain (13) , Israel (12), United States (9), Denmark (6), Ireland (The clinical syndrome among identified cases is acute hepatitis (inflammation of the liver) with markedly elevated liver enzymes. Many cases have gastrointestinal symptoms, such as abdominal pain, diarrhea, and vomiting, that preceded presentation of severe acute hepatitis, and elevated liver enzyme levels (aspartate transaminase (AST) or alanine aminotransaminase (ALT) greater than 500 IU/L ) and jaundice.
Most of the cases did not present fever . The common viruses that cause acute viral hepatitis (hepatitis A, B, C, D, and E viruses) have not been detected in any of these cases. Based on the information currently available, international travel or links with other countries have not been identified as factors.
Adenoviruses have been detected in at least 74 cases, and of the number of cases with information on molecular testing, 18 have been identified as F type 41. SARS-CoV-2 was identified in 20 cases of those tested. In addition, a SARS-CoV-2 and adenovirus coinfection was detected in 19.
The WHO notes that “it is not yet clear whether there has been an increase in hepatitis cases, or an increase in awareness of hepatitis cases occurring at the expected rate but not being detected.” “Although the adenovirus is a possible hypothesis, the causative agent is being investigated,” they specify.
In the UK, where the majority of cases have been reported to date, a significant increase in adenovirus infections in the community (especially detected in faecal samples from children) has been observed following low levels of circulation prior to the pandemic of COVID-19. The Netherlands has also reported a simultaneous increase in the circulation of adenoviruses.
However, the WHO explains that “due to improved laboratory testing for adenovirus, this could represent the identification of an existing rare result occurring at previously undetected levels that is now being recognized due to increased testing.” “.
The WHO details that although the adenovirus is currently one of the hypotheses as an underlying cause, “it does not fully explain the severity of the clinical picture.” “Infection with adenovirus type 41, the type of adenovirus implicated, had not previously been associated with this type of clinical presentation,” they point out.
Adenoviruses are common pathogens that often cause self-limited infections. They are transmitted from person to person and usually cause respiratory illnesses, but depending on the type, they can also cause other illnesses such as gastroenteritis (inflammation of the stomach or intestines), conjunctivitis (pink eye), and cystitis (bladder infection).
There are more than 50 immunologically distinct types of adenoviruses that can cause infections in humans. Adenovirus type 41 usually presents with diarrhea, vomiting, and fever, often accompanied by respiratory symptoms. Although cases of hepatitis have been reported in immunosuppressed children with adenovirus infection, adenovirus type 41 is not known to be a cause of hepatitis in otherwise healthy children.
“Further investigation is needed for factors such as increased susceptibility among young children following a lower level of adenovirus circulation during the COVID-19 pandemic, the possible emergence of a new adenovirus, as well as SARS-CoV co-infection. -2 Hypotheses related to side effects of COVID-19 vaccines are not currently supported, as the vast majority of affected children did not receive the COVID-19 vaccine Other infectious explanations need to be excluded and not infectious diseases to fully assess and manage the risk,” emphasizes the WHO.