New study provides theory on the causes of abnormal hepatitis cases in children

THere is a new theory about what is causing it Mysterious case An example of childhood hepatitis of unknown origin — and it is complex.

Two new, unpublished studies by British scientists suggest that children with hepatitis cases may have been co-infected with two different viruses and had a genetic predisposition to become seriously ill in that situation. It is theorized that there is.

Previously, the main hypothesis was that adenovirus 41, found in many infected children, causes liver damage. Adenovirus 41 is known to cause liver damage in immunocompromised children, but it has never been seen in children with an unimpaired immune system.

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However, a new study reports that the blood and liver tissue of many affected children is found to contain what is called adeno-associated virus 2 (AAV2 for short). They also found that children were infected with adenovirus or herpesvirus.

Adeno-associated virus 2 is known as Dependoparvovirus. It cannot replicate inside the host cell unless another virus is present.

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Angela Rasmussen, a virologist at the University of Saskatchewan’s Vaccine and Infectious Disease Tissues, said that, if correct, this theory does not rule out the possibility that adenovirus 41 was involved in the case.

“This suggests that AdV 41 (or another helper virus) is needed but not enough,” she told STAT by email.

“If this is correct, you need a combination of all three.”-Helper viruses such as adenovirus 41, adeno-associated virus 2, and genetic predisposition.

New research still has to go through peer review. But if they are correct, it will help explain why some medical centers treating children with liver disease saw an unusual number of cases of unexplained hepatitis last fall and spring. ..

More than 1,000 such cases have been reported to the World Health Organization from 35 countries. Of that total, 22 children died and 46 needed a liver transplant. In the United States, 355 possible cases are under investigation, says the Centers for Disease Control and Prevention. As of late June, 20 of these children needed a liver transplant and 11 died.

One new study shows that genetic variation in eight of the nine affected children is found in only about 16% of Scottish blood donors who have children. The Scottish doctor was one of the first to report a case of abnormal spring hepatitis.

Studies also suggest that the normal life disruption caused by the pandemic may have contributed to increased adeno-associated virus 2 and adenovirus infections when Covid-19 control measures began to be mitigated. Did. As a result, the number of cases of hepatitis in children will increase.

“The current outbreak represents one of many infectious diseases, including other intestinal pathogens such as norovirus, that occurred in children in the United Kingdom after returning to normal, following the relaxation of pandemic restrictions. [social] One of the papers was written by Judith Breuer, a virologist at the University College of London and the Great Ormond Street Children’s Hospital.

Alasdair Munro, a clinical researcher in pediatric infectious diseases at the British university hospital Southampton, found the treatise compelling.

“Everything seems to fit, but it’s interesting to see if further investigation can confirm that this is the cause. Hopefully some discussion can be put to sleep. increase.” He wrote On Twitter.

However, Rasmussen warned that more puzzle pieces could be found, such as how these three factors cause the damage seen so far.

“I think the important thing to remember here is that this is a correlation, not a causal one,” she writes. “To identify this as the cause requires more work, such as elucidating the mechanism.”

She also suggested that it would be nice if other groups could reproduce the findings found in these two groups of British children. Not only do some … genotyping. “

An unexplained case of childhood hepatitis ignited a hot and ugly debate on Twitter. Many scientists and doctors claim that those investigating what appears to be an outbreak ignore the obvious. The disease may be the result of a previous Covid infection.

Efforts to understand what is behind the incident, and whether or not the outbreak was actually underway, Data from the United States It showed that there was no increase in unexplained childhood hepatitis, liver transplantation for childhood hepatitis, or adenovirus 41 infection in the past year compared to before the pandemic. This does not mean that the number of cases caused by this series of triggers may not have increased, but that the total number of cases of childhood hepatitis for which no cause was found did not change.