What do we know about cases of hepatitis of unknown origin that have affected children for several months?

At the beginning of April, WHO has received an unusual report ; ten children under the age of 10 contracted severe hepatitis — one inflammation liver — in Scotland. Today, UK health authorities identify a total of 108 similar cases. On the other side of the Atlantic, the CDC just released a note indicating that five cases of pediatric hepatitis have been identified in an Alabama hospital as of November 2021; and four more since. In Europe, Spain, Denmark, Ireland but also France, with two cases reported in Lyon, are concerned.

Atypical liverworts in children

Affected children present with symptoms serious requiring hospitalization, including jaundicefrom diarrhea, vomiting and severe abdominal pain. Most of the children were able to be treated quickly, although a minority of them underwent a liver transplant. No deaths have been reported to date. Hepatitis is not common in children and the precise origin of these cases remains unknown, although doctors have a lead: a virus.

Liver inflammations can be caused by viruses,alcoholand excess of certain medications or by underlying autoimmune or genetic diseases. The problem is that recent pediatric cases are negative for hepatitis A to E, the most common cause of liver inflammation. Doctors suspect another virus but which is not known to attack the liver.

The adenovirus are viruses DNA double-stranded, large that are transmitted by contact with contaminated objects or respiratory droplets. This family includes about 50 different viruses, 40 of which can infect humans. In the majority of cases they cause respiratory infections but some types can also cause gastroenteritisfrom cystitisfrom conjunctivitis and in very rare cases, encephalitis. There is no specific treatment for adenovirus infection.

Adenovirus type 41 suspected culprit

Doctors are particularly interested in adenovirus type 41 which is known to cause gastroenteritis, often combined with respiratory damage, in children. Cases of hepatitis caused by adenovirus type 41 infection have been documented but only in immunocompromised children in healthy children, this virus is not known to cause such a symptom.

Sick children in the United States have all tested positive for adenovirus type 41, the remaining cases are under investigation. ” If an adenovirus is responsible, it could be a new variant that can cause liver damage in children whose immune system is naive. But we need to know more to be sure. On the other hand, if adenovirus is the culprit of hepatitis in healthy children, we need to look for other infections or environmental causes that could exacerbate the inflammation caused by adenovirus. “, explains Zania Stamataki, associate professor in viral immunology at the Center for Liver and Gastrointestinal Research from Birmingham.