Three separate studies, which were published on Thursday in the journal Nature, suggest that adeno-associated virus 2, or AAV2, may be responsible for an epidemic of acute severe, unexplained hepatitis in children in 2022.
In the period between April and July 2022, hepatitis, a condition characterized by inflammation of the liver, was found in more than 1,000 children globally, including at least 350 in the US. According to the World Health Organization, 22 children perished and nearly 50 people required liver transplants.
Excerpts from the Study
The disease may be related to AAV2, according to a recent study. Unless there is another “helper” virus present, such as an adenovirus or a herpesvirus, this prevalent childhood virus cannot replicate itself. Nearly all of the kids who had unexplained acute hepatitis had AAV2, and many of them had numerous helper viruses, the researchers discovered.
The timing of the outbreak may have been related to the worldwide relaxation of Covid-19 pandemic restrictions after periods of relative isolation, though researchers can’t be certain of this.
Dr. Frank Tacke, a German gastroenterologist who was not involved in the research but wrote an editorial that was published alongside the new studies, stated that “Children were suddenly exposed to a barrage of viruses after lockdowns or had poorly trained immune systems that led to an increased susceptibility to otherwise harmless viruses.”
WHO’s Science in 5: Hepatitis outbreak in children – 26 August 2022
The Need for Further Research
Previously, scientists thought that the outbreak may have been caused by the human adenovirus, which usually causes a mild cold or flu-like illness. This theory, however, was challenged by the fact that adenovirus typically only affects individuals with extremely compromised immune systems and that multiple viral strains suggested that a single viral strain could not account for the outbreak.
According to Tacke, the new findings “are likely to spark controversy and could influence disease management.” For treatment, it will be crucial to identify the cause. Antiviral medications would be suitable if AAV2 was to blame. Drugs that weaken the immune system may be required if it is the result of an unusual immune reaction. Although the consistent results on two continents offer compelling proof, there are still some questions, such as whether AAV2 directly contributes to liver damage or is “just a bystander.”
