Since April 2022, child hepatitis symptoms caused by mysterious reasons have increased more than usual in 25 countries. Scientists are eyeing a novel variant of Adenovirus as the main culprit.
Child hepatitis is nothing unusual in both developing and developed countries worldwide. Exposure to hepatitis viruses, toxic chemicals, mother-to-child transmission, and drug abuse are the primary causes.
However, health organizations worldwide are facing an unusual spurt in the number of severe hepatitis cases in children under 5. The WHO confirmed 169 cases of hepatitis of unknown origin in April 2022. Guess what? The number reaches 450 by 15 May 2022.
Countries including the USA, the UK, Spain, Netherland, Israel, Japan, and Denmark are seeing the most increase in hospitalized cases. Till May, 160 and 110 cases have been reported in the UK and USA, respectively.

Till now, one child has died due to the severity of the symptoms. The most alarming thing is around 10% of the admitted children have needed liver transplantation. The typical hepatitis treatment is primarily supportive where the liver recovers automatically, supported by hydration and temperature management.
Scientists around the world are working on multiple hypotheses to explain the outbreak of this unusual hepatitis. And till now, a novel variant of Adenovirus seems to be the most plausible.
Adenovirus is a pretty common pathogen responsible for flu-like symptoms. Its impact on the liver was not unusual but was not observed before at such severity. The severity of liver injuries in children with unusual hepatitis makes Dr. Zania Stamataki, a viral immunology professor at the University of Birmingham, believe that “this could be a new variant of adenovirus.”
In the US, more than half of the cases have tested positive for adenovirus. The number is 60% across Europe, whereas it’s around 72 percent in the UK.
According to the UK Health Security Agency research, a few cofactors, including SARS-CoV-2 infections, are responsible for this perilous immunopathology. Among the other cofactors, susceptibility emerging from the lack of prior exposure due to the COVID pandemic, coinfection with SARS-CoV-2, toxin, drug, and environmental exposure are all on the table.
The unusual pattern of child hepatitis symptoms was first discovered in the US by Dr. Markus Buchfellner of the University of Alabama at Birmingham. He and his team also hypothesized the impact of lockdown on reduced exposure and eventual severity of hepatitis widespread among the children.