Since the WHO Communiqué on Acute Idiopathic Hepatitis Outbreaks – in the United Kingdom of Great Britain and Northern Ireland on 15 April 2022, there have been a series of further reports of acute Idiopathic hepatitis cases in young children.
Dr. Abdel Nasser Abu Bakr, Director of the Infection Risk Preparedness and Prevention Unit in the Eastern Mediterranean Regional Office of the World Health Organization, told Al Arabiya.net that it was not yet clear whether there was an increase in the number of hepatitis cases, or an increase in awareness of hepatitis cases. Occurring at the expected rate but not observed. Although adenovirus is a possible hypothesis, investigations are underway to discover the causative agent of the disease.
As of 21 April 2022, at least 169 cases of acute hepatitis of unknown origin have been reported from 11 countries in the WHO European Region and one country in the WHO Region of the Americas. Cases have been reported in the United Kingdom of Great Britain and Northern Ireland and other countries. The ages of the detected cases ranged between one month and 16 years. Of these, seventeen children (about 10%) required a liver transplant, and at least one death was reported.
Abdel Nasser added that the clinical syndrome among the discovered cases is acute hepatitis with a marked increase in liver enzymes. Several cases have reported gastrointestinal symptoms, including abdominal pain, diarrhea, vomiting preceding the onset of severe acute hepatitis, increased levels of liver enzymes (aspartate transaminase (AST) or alanine aminotransaminase (ALT) greater than 500 IU/L) and jaundice. Most of the cases did not have a fever. The common viruses that cause acute viral hepatitis (the hepatitis A, B, C, D, and E viruses) were not detected in any of these cases. Based on the information currently available, international travel to or transit through other countries was not considered a cause of the disease.
Mysterious liver disease – iStock
Adenovirus was detected in at least 74 cases, and among the cases with information from molecular testing, 18 were identified as type F41. The SARS-CoV-2 virus that causes COVID-19 was detected in 20 of the tested cases. . Furthermore, 19 co-infections with SARS-CoV-2 and adenovirus were detected.
The United Kingdom, where the majority of cases have been reported to date, recently noted a significant increase in adenovirus infection in the community following low levels of transmission at the start of the COVID-19 pandemic. The Netherlands also reported a simultaneous increase in community transmission of adenoviruses. However, due to enhanced laboratory testing for adenovirus, this may be a finding of an existing rare result occurring at previously undetected levels and now known due to increased testing.
Nasser added that it should be borne in mind that adenovirus is very common and, as the Scotland report showed, is increasing. Hence, the cases can only be an associated infection rather than a causal one. Also, adenovirus has DNA in its center (compared to RNA, such as SARS-CoV-2) so that it can survive longer. The case’s viral loads were low, which may indicate a longstanding infection and do not explain the sudden onset of severe liver damage.
public health response
Nasser confirmed that the organization is conducting more investigations in the countries that discovered cases, and the investigations include clinical history and exposure history in more detail, toxicology testing, and additional viral/microbiological tests. Affected countries also started enhanced surveillance activities.
50 types of adenovirus
Although adenovirus is currently one of the hypotheses for the underlying cause of this disease, it does not fully explain the current situation. Infection with type 41 adenovirus, the type of adenovirus most likely to cause this disease, has not previously been associated with such a clinical presentation. Adenoviruses are common pathogens that usually cause a self-limited infection, spread from person to person, and mostly cause respiratory disease, but, depending on the type, can also cause other diseases, such as gastroenteritis, conjunctivitis (pink eye) and inflammation of the eye. Bladder. There are more than 50 types of immunologically differentiated adenovirus that can cause infection in humans. Type 41 adenoviruses usually present with diarrhea, vomiting, and fever, often with respiratory symptoms.
Although there have been reports of cases of hepatitis in immunocompromised children with adenovirus infection, type 41 adenovirus is not known to cause hepatitis in healthy children.
Nasser stressed the need for further investigation of factors such as increased susceptibility to infection among young children after the low level of adenovirus transmission during the COVID-19 pandemic, and the possible emergence of a new adenovirus, as well as co-infection with SARS-CoV-2. Hypotheses regarding the side effects of COVID-19 vaccines are not currently supported because the vast majority of infected children have not received the COVID-19 vaccine. Other explanations related to infectious and non-infectious agents must be excluded in order to fully assess and manage risks.