Italy is the European country that has reported the highest number of cases. In the world at least 14 children have died. Dual infection (even silent) could overload the immune system when Sars Cov-2 hides in the gut
There are more and more cases of acute hepatitis of unknown origin affecting children. The United States they are investigating 180 cases, up from 109 reported two weeks ago (only 7% are in the last few days, the others have only been accounted for now, when health authorities have expanded their investigations). To date, there are six deaths in the US. Fifteen children, almost all preschoolers, needed a liver transplant. Even the United Kingdom, the first country to sound the alarm, continues to report new cases: inlatest bulletin there is talk of 197 children affected by the mysterious hepatitis, 34 more than a week ago. Of these eleven needed a liver transplant, one died. The Cwithin the European Union for the Prevention and Control of Diseases European speaks of 125 cases identified in 14 European countries. Italy is the country in Europe that reported the highest number of unknown hepatitis: 35, followed by Spain (26) and Portugal (12). Almost 700 cases of unexplained hepatitis have been identified globally; at least 14 children died.
Hepatitis has multiple causes, but in these cases the known viruses that cause hepatitis (hepatitis A, B, C, D and E) have been excluded and the origin still remains shrouded in mystery. focused on the potential role of an adenovirus, specifically adenovirus 41, which has been detected in many cases. The virus is common and typically causes gastrointestinal disease, but does not cause liver damage in healthy children (possible in immunosuppressed children but young patients have so far all been in good health before contracting hepatitis).
Health investigators are evaluating a number of hypotheses. Did this phenomenon occur previously but at numbers so low that it was not detected? L‘adenovirus changed in such a way as to be capable of attacking the liver? Is there a combination of factors at play, such as the effect of another virus (also Sars-CoV-2, found in 15% of British patients) or toxin in tandem with an adenovirus infection? Are children more susceptible to the effects of an adenovirus infection due to lack of exposure to common viruses during the Covid-19 pandemic? Is an adenovirus really involved in all this?
Preliminary genomic evidence shows that not only adenovirus 41 was found in children, but other adenovirus strains as well, although 41 was prevalent. The anti-Covid vaccine factor has already been excluded from the beginning: many children are under the age of five and have not been vaccinated.
The prevailing hypothesis: adenovirus and Sars-CoV-2
So far a double action due to the coexistence of the adenovirus and the SarsCoV2 virus is the most likely hypothesis to explain the origin of the cases of hepatitis that have been occurring in children in recent weeks, and the World Health Organization is also focusing on this. .
In fact, one of the hypotheses that hepatitis cases are the result of a past Covid-19 infection followed by another viral infection, perhaps adenovirus 41. According to this theory, some children do not completely clear the coronavirus after a mild infection, and the virus remains in their gastrointestinal tract, thus keeping the immune system extremely active. Driven by this second viral infection, components of the immune system go into overdrive, damaging the liver, in a process called superantigen-mediated immune activation. Basically, la second infection triggers a cascade of effects which results in hepatitisAnd. If a child has such a viral reservoir that persists for a while and then has a viral intestinal infection – possibly due to adenovirus – then one can imagine that this could potentiate this superantigen effect he speculates. Petter BrodinProfessor of Pediatric Immunology at Imperial College London on The Lancet Gastroenterology and Hepatology.
The hypothesis put forward by Petter Brodin and his colleague Moshe Arditi is currently the key to the work of the World Health Organization which looks with interest at this possibility. The main hypothesis remains a possible link c with adenovirus and / or with Sars-CoV-2 reported the WHO expert Philippa Easterbrookduring the periodic briefing with the press a few days ago.
It also investigates how these two infections could act together as co-factors, either by increasing the susceptibility of children or by creating an abnormal immune response. A previous Covid infection in babies, perhaps from some time ago, may have persisted and remained in the intestine. And then a subsequent adenovirus infection could have resulted in the activation of the immune system and inflammation. This is just a hypothesis – said Easterbrook, who is part of the WHO Global Hiv, Hepatitis and Sti Program – There was no data based on studies on children to support this and that is why it is so important that the Covid test, among other tests, it is systematically performed to detect both past and present infection and for all children, so as to be able to make comparisons between cases reported in different countries.
Also Giuseppe Remuzzi director of the Mario Negri Institute espouses this hypothesis to explain the mysterious pediatric hepatitis. Underlying it is the possibility that in children who have been infected with SarsCoV2, this virus may have hidden and nestled. This could also happen, for example, if the children have had the infection but no symptoms, or if they have passed the infection: If the virus is no longer detected, it does not mean that there is no reservoir. L’intestineRemuzzi continues, it could be the place where the virus hides; the latter would constantly release its proteins, which together would begin to act as a super-antigen, that is, as a single agent capable of stimulating the reaction of the immune system. In particular, they would come toActivate T cells, who usually launch their attack on a specific target; however, the super-antigen manages to divert them and eventually the immune cells begin to release a huge amount of cytokines, the substances responsible for inflammation. The same mechanism that causes the so-called cytokine storm and that triggers multisystem disease in children. This process can also occur when a child who has been infected with SarsCoV2 comes into contact with adenovirus, especially that of subtype 41-F, which is seen in many cases of abnormal hepatitis. According to Remuzzi, it would be the most convincing hypothesis because it manages to give a place to all the factors observed so far in abnormal hepatitis, namely the fact that most children have adenovirus, that adenovirus is circulating at the same time as SarsCov2, which is not known hepatitis viruses are involved and that the viral origin of the cases is clear. To get the answer, he continues, the serum of children who have had abnormal hepatitis should be analyzed to understand how many have been exposed to the SarsCov2 virus and, to understand if they might still have a reserve, it would be necessary to analyze the presence of the virus in the faeces. Alone – he concludes – adenovirus 41-F not able to give the disease.
The dogs hypothesis falls
Other scientists seem more skeptical of the idea that Covid is involved in the new pediatric hepatitis or at least not unbalanced. Calum Sempleprofessor of child health and epidemic medicine at the University of Liverpool, told a STAT of having moved away from the idea of a possible link with Covid: We do not completely rule out the involvement of the coronavirus, but I think Covid is now at the bottom of the list. In the penultimate UK report, health authorities noted that many cases were from families who own dogs or who had had contact with dogs. However in the latest report On Friday the researchers wrote: There is no difference between children with dog contact and those without dog contact in disease patterns or virological detections concluding that this is no longer an active line of investigation by health agencies. public health.
May 23, 2022 (change May 23, 2022 | 13:28)
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