A wave of acute hepatitis is affecting British children, what we know here – Edition du Soire West-France

Conor MEEHAN, Lecturer in Microbiology, Nottingham Trent University (UK)

The SARS-CoV-2 responsible for Covid has not yet been removed from the list of suspects. But the most likely culprit for the severe hepatitis wave that is now affecting children in the UK is another virus, adenovirus.

In recent months, there has been a rapid increase in cases of severe hepatitis in children under 10 years of age in the UK. Between January and April 8, 2022, 74 cases were reported to the UK Health Security Agency (UKHSA), of which 49 were in England, 13 in Scotland and 12 more in Wales and Scotland. Northern Ireland. Other isolated cases have also been identified in the United States, Spain and Ireland. As of May 1, 2022, the World Health Organization (WHO) has received 228 potential cases from twenty countries. According to Public Health France, more than 50 cases were under investigation, including two in France.

Severe hepatitis is very rare in children, and the cause of this very unusual increase in cases has not yet been identified. The most probable theory is that hepatitis is caused by a viral infection. Could they be linked to infection with SARS-CoV-2, the coronavirus that causes Covid-19? Is there another explanation?

What is “hepatitis”?

First, let’s look at what hepatitis is and how it is associated with viral infections. The term “hepatitis” describes inflammation of the liver.

Inflammation is an indeterminate immune response that occurs after an infection or injury. This is a sign that the body is trying to stop a possible cause of illness. In children, the symptoms usually include some (but not all) of the following: dark urine, gray stools, yellowing of the skin and eyes (called jaundice), and high temperature.

With proper medical care, hepatitis can usually be cured. Nevertheless, it happens that some patients require a liver transplant for their condition. According to the World Health Organization, six British children had to undergo such a transplant in mid-April.

The causes of the disease can vary, but hepatitis in children is usually associated with a viral infection. Viruses are usually five hepatitis viruses: A, B, C, D, and E. Other viruses, such as adenoviruses, can also cause hepatitis, but are rarely involved.

What is unusual about pediatric hepatitis is that none of the five hepatitis viruses have been detected in young infected patients. Which effectively eliminates the most common cause of the disease and leaves the public health authorities in search of an explanation …

Adenovirus and hepatitis

Adenoviruses are usually responsible for human infections, especially in children. Almost all of them have been infected with adenovirus at least once before the age of ten.

Typically, these viruses cause infections of the lungs and respiratory tract, resulting in common cold symptoms or, sometimes, pneumonia. In some cases, initially in children five years of age or older, adenoviruses can cause “pharyngoconjunctival fever” (Pool fever, Literally “pool fever”), which causes sore throat, fever and eye inflammation.

However, sometimes adenoviruses cause hepatitis in immunocompromised patients (i.e., those whose immune systems are not functioning properly, such as those who have had an organ transplant or are undergoing cancer treatment).

But it is rare to see such cases, especially in children who do not appear to be immunocompromised. If an adenovirus is actually the cause of these cases, it could mean that a new variant has emerged, capable of causing the disease more easily.

Hepatitis refers to inflammation of the liver. (Image: Explosion / Shutterstock)

Other possible causes

Since adenovirus infection is a common infection in children, and can result in hepatitis, it is tempting to consider this explanation as the most probable. But in other situations it must be explored nonetheless.

In the case observed, for example, autoimmune hepatitis may occur: in this disease, it is not a virus or other pathogen that attacks the liver, but the organism itself. However, this type of hepatitis is rare, affecting around 10,000 people in the UK alone. What’s more, autoimmune hepatitis is more common in women around the age of 45. In view of these factors, it is highly unlikely that this disease is the cause of the observed outbreak in children.

Another hypothesis suggests that Covid-19 may be the cause of this field of hepatitis. Indeed, SARS-CoV-2 has been detected in some infected children (isolated cases of hepatitis in covid patients have also been reported, but these are rarer than in autoimmune hepatitis and are mainly seen in adults with severe covid forms).

In this regard, it is important to note that none of the children infected with hepatitis in the UK received the SARS-CoV-2 vaccine. So there is no reason to believe that vaccines designed to fight Covid-19 have anything to do with this peak of hepatitis.

Another possibility: these hepatitis can be caused by the interaction of different viruses (for example, an adenovirus and a coronavirus that will infect the same child at the same time).

Finally, a completely different virus, which has not yet been detected, can also cause this disease.

And now?

The UK Health Safety Agency advises parents and carers to be vigilant for the symptoms of hepatitis.

Although adenoviruses currently appear to be the most likely culprits, more research is needed to confirm this hypothesis and to rule out other possibilities, such as infection by a new virus. Perhaps we will discover that there are no common sources of hepatitis and that their causes vary from child to child.

Either way, in the face of such unusual medical conditions and the ongoing Kovid-19 epidemic, we should always keep in mind that coronavirus is a potential suspect. However, we should not systematically blame everything on it, because it can distort our view of things.

In conclusion, if an adenovirus is actually found to be responsible for this condition, how can we protect ourselves from it and thus reduce the risk of serious complications?

Adenoviruses are spread through air and touch. So the main precautionary measures are for adults and children alike, to wash their hands properly and adopt good hygiene habits, for example coughing up their elbows without their hands.

The original version of this article was published Conversation.

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