RIO A mysterious kind of acute hepatitis has attracted the attention of health authorities in various countries around the world in recent weeks. The disease, which affects children and is already being studied in Brazil, is not caused by any of the known hepatitis viruses (A, B, C, D and E) and, among its causes, may have an as yet unclear relationship between them Covid19 and a type of adenovirus.
The World Health Organization (WHO) registered 348 cases of illness up to this week. Most children had gastrointestinal symptoms, jaundice, and in some cases acute liver failure and death. THAT Ministry of Health created a situation room to monitor the 41 suspected cases of acute childhood hepatitis of unknown cause registered to date in the national territory. a teenager needed undergo a transplant in the hinterland of Pernambuco on Friday the 20th and the case will be investigated.
The first hypothesis was raised by health authorities in the Great Britain. The first cases were registered there and it was hepatitis caused by an adenovirus. Studies have shown that up to 70% of patients have tested positive for adenovirus 41F. It affects more children, adolescents and immunocompromised people. It causes a cold or intestinal problems.
“Initially it was assumed that the adenovirus would be the cause of acute hepatitis, but the fact is that it did not appear in all cases,” explained Marcelo Simão, an infectious disease specialist at the Federal University of Uberlândia in Minas Gerais. “In many children with severe illnesses, it has not been possible to isolate the virus; and in some who underwent transplantation, the virus was not found in the removed liver.”
Experts also noted that many children had contracted Covid19 before acute hepatitis. A study published in the Lancet last week then proposed a new hypothesis. According to the study, a combination of the two infections would cause acute liver disease.
Particles of SarsCoV2 that remain in the intestinal tract of children would serve as a trigger for an exaggerated immune system response to subsequent infection by the virus. Adenovirus 41F. The coronavirus spike protein is considered a superantigen. It makes the immune system more sensitive. It would potentiate the effects of adenovirus 41F. Usually this virus does not cause more serious problems.
The response would be similar to that caused in multisystem inflammatory syndrome. This condition has been identified in children with longterm Covid. In these cases, abnormal activation of the immune system occurs due to the superantigen. It triggers an extremely inflammatory autoimmune response. Any subsequent contact with an adenovirus could provoke an even stronger reaction from the body. This can be the case with acute hepatitis.
“The most accepted hypothesis today is that this hepatitis is caused by an exaggerated immune response caused by the combination of these two viruses, which eventually attacks the liver,” said Simão, whose name is on Stanford University’s list of most influential scientists in the world. “Why the liver? We do not know yet.”
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The hypothesis most accepted today is that this hepatitis is caused by an exaggerated immune response caused by the combination of these two viruses.
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Marcelo SimaoInfectologist at the Federal University of Uberlândia
According to Simão, the question of why cases of acute hepatitis have only been discovered now, two years after the start of the pandemic, has not yet been clarified. A possible explanation would be related to the variant of SarsCoV2 currently in circulation.
For the President of the Society of Infectious Diseases of the Federal District, José David Urbaez Brito, the hypothesis of the combination of the two viruses is currently the most likely to explain cases of acute hepatitis in children, although it is still ongoing.
“What’s different in this current moment in our lives is that we’re suffering from the continuous modulation of a pandemic,” Brito said. “We are being bombarded minute by minute by an infectious agent circulating on a gigantic scale. Anything new that comes up could have something to do with it.”
Data from the WHO and studies from Israel, the USA and India support the hypothesis. The Israeli work, coordinated by Yael Mozer Glassberg of Schneider Children’s Medical Center, showed that 11 out of 12 children with hepatitis had Covid19. However, none of them tested positive for the adenovirus.
WHO Europe pointed out in a report published this month that up to 70% of children under the age of 16 who develop acute hepatitis had previously been diagnosed with Covid19. In addition, experts explained, other children may have had the disease mildly or even asymptomatically; that is, without an official diagnosis.
A case study conducted in the USA and published in the Journal of Pediatric Gastroenterology and Nutrition analyzed the case of a threeyearold girl. The girl developed liver failure a few days after recovering from mild Covid.
“The findings from the patient’s liver biopsy and blood tests are consistent with a type of autoimmune hepatitis that may have been triggered by Covid,” explained pediatrician Anna Peters, a gastroenterologist at Cincinnati Children’s Hospital Medical Center in the US who is responsible for the study , when you comment on the work.
According to the expert, it is impossible to prove the existence of a direct link between Covid and liver disease. But the virus could have triggered an abnormal immune response. She would be the liver attack generator.
A survey conducted in India last year followed 475 children who had contracted Covid in the country. 47 of them had acute hepatitis. Recently, as new cases surfaced in Europe and the US, researchers turned their attention to this 2021 Indian study.
“The only commonality we found among these children was that they were all infected with Covid,” said the study’s lead author Sumit Rawat, associate professor at the Bundelkhand School of Medicine in Madhya Pradesh, India, in an interview with international agencies. “Proof that Covid does in fact cause this hepatitis will require many more studies, but an important clue is that hepatitis cases fell when SarsCoV2 stopped circulating in the region and rose again when Covid was high.”
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The only commonality we found among these children was that they were all infected with Covid.
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Sum RawatProfessor at the Bundelkhand School of Medicine
A connection between hepatitis and vaccine has been completely ruled out
However, the link between cases of acute hepatitis and the vaccine against Covid has been completely ruled out. There is no direct link between vaccination and hepatitis. In addition, the vast majority of children with acute hepatitis were less than five years old. That means they had not been immunized against Covid.
Experts believe emerging viral pandemics and their eventual impact are likely to become more common due to human impact on the environment and climate.
“We live in a complicated world with many new diseases, many new viruses; Bacteria that we didn’t take care of are now causing serious diseases,” Simões said. “Despite technological advances, the challenges are increasing.”
José David Urbaez Brito reminded us that it is no coincidence that we live in the socalled Anthropocene. It is the first time that a living being, in this case man, has changed its environment so profoundly and often irreversibly that it has come to be called a geological age.
“Humans have altered geological and ecological chains, significantly increased global temperature, which has a profound impact on the dynamics of infectious agents, particularly viruses, which are very simple forms,” Brito said. “Narratives have the power to rationalize what is happening and leave us alienated; But the truth is that we are living in an apocalyptic moment of gargantuan proportions and the current pandemic is one of the symptoms of that.”