What was very worrying for the health professionals who report these cases is the severity of the disease in these young, otherwise healthy children. Seventeen needed a liver transplant and one child died of liver failure.

The number of transplants is much higher than what is usually observed in similar time periods in previous years. Although acute hepatitis is not uncommon in children, these latter elements are unprecedented, and so far, only partially explained.

One suspect is an adenovirus infection. According to the United Kingdom Health Insurance Agency, adenovirus was the most common pathogen found in 40 of the 53 confirmed cases examined in the United Kingdom. The agency said that “research is increasingly showing that an increase in severe cases of hepatitis may be associated with adenovirus infection, but other causes are still being actively investigated.”

Adenoviruses Adenoviruses are a large group of viruses that can infect a wide range of animals as well as humans. They got their name from the tissue from which they were originally isolated: the adenoids (tonsils).

Adenoviruses have at least seven different species and within these species, there are genetic variants just as we see with coronaviruses and other viruses. In this case, instead of variants, they are referred to as adenovirus subtypes.

Adenoviruses cause mild illness in humans, most of the time. Some species cause respiratory-like illnesses, such as croup in young children and babies. Others cause conjunctivitis and a third group causes gastroenteritis.

The subtype associated with the current outbreak of acute hepatitis in children is called adenovirus subtype 41, with the virus being detected in at least 74 cases to date. Subtype 41 belongs to the adenovirus cluster usually associated with mild to moderate gastroenteritis. essentially a stomach upset with symptoms of diarrhea, vomiting and abdominal pain.

In most children and adults with a healthy immune system, adenoviruses are a simple nuisance, resulting in a disease that is expected to pass in a week or two. Viral hepatitis from adenovirus infection has only been reported in the past as a rare complication.

Due to the number of cases and the severity of the disease in children, scientists are urgently investigating the cause of the epidemic. At the beginning of the epidemic, epidemiologists tried to identify the links between these cases and, of course, to identify the cause of viral hepatitis. It quickly became clear that this was not just a small, isolated set of cases.

Data from the Scottish National Health Service revealed that none of these children lived in a distinct geographical pattern (such as near an open water source), that the mean (median) age at admission to hospital was four years and no other obvious characteristic, such as nationality or gender, were found to be related to the disease. Similar findings were reported by the US Centers for Disease Control and Prevention.

Because some of the COVID vaccines used adenoviruses, some people on social media wondered if the vaccines were the cause of the epidemic. However, none of the cases reported in the UK had been vaccinated against COVID, and vaccines for COVID using adenoviruses use an unrelated virus that cannot multiply.

Questions to be answered Researchers have yet to find a direct causal link between adenovirus 41 and these cases of hepatitis. Are there other factors that complicate the onset of serious illness, such as co-infection with another virus, such as coronavirus? Sampling the population (for both adults and children) to get an idea of ​​how prevalent adenovirus 41 is in these reference areas versus other low to zero impact areas would help stabilize the connection. Scientists must also discover the genetic composition of the virus. Has it changed significantly from the reference information we have on it? It will be crucial to understand the immune response in these cases to other mild adenovirus infections. Research on prevention (vaccination) and treatment options, such as antiviral drugs, must also begin.

Hopefully we have some answers – and treatments – soon. Meanwhile, parents should be wary of hepatitis symptoms in their children, such as yellowing of the eyes and skin (jaundice), dark urine, pale skin, itchy skin, tiredness and abdominal pain. (This story has not been edited by Devdiscourse staff and is automatically generated by a syndicated flow.)