First Great Britain, then Denmark, Ireland, Holland, Spain and now France. Since the beginning of April, about 100 cases of acute hepatitis affecting children have been identified in Europe, according to the European Center for Disease Control and Prevention (ECDC). Suspected cases are also being investigated in Alabama and North Carolina, USA. “Investigations are ongoing in all countries reporting cases. At present, the exact cause of hepatitis is unknown. says ECDC.
Very young children affected
In France, two potential cases were reported by Lyon University Hospital before they were ruled out, one had been shown to be of genetic or metabolic origin (studies are still ongoing) and the other of viral. If these severe inflammations of the liver have not resulted in any death so far, six children have had to undergo a liver transplant across the Channel.
“Severe hepatitis in children is not uncommon. What is, however, is that it affects very young children – between 1 and 5 years – and requires a liver transplant”. explains Dr. Alexandre Fabre, a pediatrician specializing in hepato-gastroenterology at Timone Hospital in Marseille.
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At his hospital, however, there are no signs of this mysterious disease whose main symptoms are jaundice, abdominal pain and vomiting. “This is quite positive, because we are also a transplant center and cover a very large population group in Paca, including 1 million children”, emphasizes the doctor.
No obvious connections between the cases
This outbreak of unexplained hepatitis nevertheless raises fears of a new epidemic, while Covid has not disappeared. “At the moment we do not even know if the cases in the different affected countries are comparable, temperament Professor Emmanuel Jacquemin, Head of the Hepatology and Pediatric Liver Transplant Department at the Bicêtre Hospital in Paris. In my opinion, there is no evidence that an epidemic has started. »
Only identification of the exact cause of these hepatitis will make it possible to be sure. Currently, the only available data are those from a Scottish study, conducted on 13 patients between 1eh January and 12 April 2022. It shows that the infection would not be of toxic origin (ingestion of paracetamol in large quantities for example) and that at first glance there would be no obvious link between the different cases.
Several hypotheses on the table
Several hypotheses are on the table: metabolic disease of genetic origin, immune hematological disease, autoimmune hepatitis … But the viral infection seems to be the most plausible cause in Professor Jacquemin’s eyes. “Maybe an adenovirus?” he suggests. However, this virus, which is responsible for colds and gastroenteritis, was not detected in the analyzes of Scottish patients.
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“Our British colleagues believe that it may in fact be a new tribe, Alexandre Fabre explains doubtfully. If a common pathogen were involved, there would be clusters of infection, as seen with recent cases of E. coli. But that does not seem to be the case. Unless this strain only operates on a specific genetic background, some people are more likely to catch it or have severe forms, as with Covid. »
Furthermore, the Scottish study does not rule out a serious form of Covid or contamination with an as yet unknown variant. Other options: a co-infection (Covid coupled with another disease), a post-infectious reaction to a virus (on Pims model, the pediatric multisystem inflammatory syndrome, induced by Covid) or even an immune debt “contracted by some children.
“It’s a vague concept that does not yet have formal evidence, but the idea would be that with the change in viral circulation due to Covid and barrier measures, infections that would have been benign become more serious in the air. Especially if “they are small children whose immunity has been built in the shadow of Covid. The person responsible would therefore be the time of exposure to this or that virus.” formulates the doctor. One thing is for sure, he says: “The occurrence of these unusual cases cannot be the result of chance. There is something.”
What are adenoviruses?
– Definition: Adenoviruses were discovered in the 1950s and are a group of DNA viruses that infect mucous membranes. This family includes dozens of very common viruses, not all of which cause symptoms. The majority of the population is infected before the age of five.
Diseases: the most common adenovirus infections are moderate: ocular (conjunctivitis), respiratory (pharyngitis, bronchitis and pneumopathy) and the digestive tract (gastroenteritis). Infections can be more serious or even fatal to immunocompromised people.
– Infection: it occurs through airway droplets or fecal-oral route with epidemic peaks (winter and spring). These are often communities (crèches, schools, etc.). Prevention consists of hygiene measures (hand washing, etc.)