Health experts around the world are investigating an increase in the number of cases of hepatitis, or inflammation of the liver, in children. The disease was first reported in a small number of children in the UK between January and April this year, but there have since been reports of cases in Europe, parts of the US and one case in Asia.
According to the World Health Organization (WHO), as of April 21, 2022, at least 169 cases of acute hepatitis of unknown origin have been reported. Countries that have reported cases include the UK, US, Spain, Israel, Denmark, Ireland, the Netherlands, Italy, Norway, France, Romania and Belgium. On Monday, Japan announced its first case and Canada said it was also investigating reports of similar cases. Globally, confirmed cases are found in patients aged one month to 16 years. Seventeen children, approximately 10 percent, have required a liver transplant. At least one death has been reported.
Although hepatitis in children is not unheard of, the severity of these infections makes them rare. The fact that these infections are occurring in previously healthy children is also a cause for concern. The fact that some of these children required a liver transplant makes understanding the cause behind this mysterious disease even more urgent.
More unusual still, these cases are not linked to any of the five typical strains of hepatitis: A, B, C, D and E. The children involved tested negative for these specific viruses.
What is hepatitis?
Hepatitis is a broad term that refers to inflammation of the liver.
The liver is a vital organ located in the upper right part of the abdomen. It has over 500 known functions including filtering the blood, aiding in digestion, assisting in the control of blood glucose levels, regulating and producing proteins, cleansing the blood of drugs and other poisonous substances, controlling iron levels in the blood and resist infection by producing immune factors. and the removal of bacteria from the bloodstream.
When the liver becomes inflamed, as is the case with hepatitis, these functions can be affected.
Hepatitis is usually the result of a viral infection (hepatitis A, B, C, D, E) or liver damage caused by alcohol consumption, and in some cases can occur as a result of the body’s own immune system attacking liver cells. Some types of hepatitis will pass without serious problems, while others can be long-lasting (chronic) and cause scarring of the liver (cirrhosis), loss of liver function, and, in some cases, liver cancer.
In the early or acute stages, children and adults with hepatitis may not have symptoms and may not realize they have it. But if symptoms do develop, they are often non-specific and can include:
- muscle and joint pain
- A high temperature
- feeling and being sick
- Lethargy
- Stomach ache
- dark urine
- Pale gray stools
- Yellowing of the eyes and skin (jaundice)
Children with these symptoms, particularly if they are not calming down, should be seen by a doctor. Most types of hepatitis can be treated or resolve on their own, but in some cases the disease can progress to liver failure, in which the liver stops working altogether. If this happens, a liver transplant is needed.
What is causing this sudden increase in hepatitis in children?
The cases of hepatitis seen in children so far have not been caused by the usual hepatitis viruses. Experts believe that the disease is being caused by a group of viruses known as adenoviruses – a common group of viruses known to cause a range of illnesses, from upset stomachs to upper respiratory tract infections, predominantly in children.
There are 88 types of adenoviruses known to infect humans and they are grouped into seven different species, A through G. They are spread through close personal contact, respiratory droplets, and contaminated surfaces.
Most adenovirus infections are self-limiting in healthy children and adults and are managed with supportive measures such as fluids and rest. Fatal infections can occur in immunocompromised children and adults and less frequently in healthy ones. They do not usually cause infections as serious as hepatitis in otherwise healthy children, although individual case reports of this have been published in the past. documented.
Although the number of children who have been identified with hepatitis worldwide remains relatively small, it is still more than health professionals are used to seeing and has prompted health organizations to publish alerts say that urgent investigations are being carried out.
Research will focus on whether a group of viruses that usually cause mild infection in most people has changed, or whether it is the host’s response to the virus that has been altered.
Scientists and doctors are now investigating whether there has been a change in the genetic makeup of the virus that could trigger liver inflammation more easily. The UK Health Security Agency (UKHSA) says that a strain of adenovirus called F41 appears to be the most likely cause (PDF). This is not a new strain of adenovirus and usually causes Diarrhea in children and is commonly spread through the fecal-oral route. It is currently unknown if there is a new variant of the F41 adenovirus that makes it more dangerous for the liver in children or if certain children are responding to it in an unusual way.
One potential hypothesis scientists are investigating is that children were less exposed to these common viruses while COVID-19 restrictions were in place, preventing social mixing. Now, as things open up and kids start to mingle again, they’re suddenly exposed to a series of viruses in quick succession and their immune systems overreact, eventually leading to liver inflammation.
Although most of the children who have had mystery hepatitis were under the age of five, some were older and this theory, although widely held, is unfounded for them as they are likely to have been exposed to adenoviruses when they were younger. before the pandemic started.
Another possible hypothesis is that a previous infection with the SARS-CoV-2 virus could be related to the increase in cases of hepatitis in children. Some, but not all, of the UK children who were diagnosed with hepatitis tested positive for COVID; the theory being investigated asks whether a previous or current infection with COVID-19 could make children more susceptible to hepatitis when they are later infected with an adenovirus. Although isolated cases of hepatitis have been reported in patients with severe COVID, this is rare.
It is important to note that none of the children in the UK, which has seen the majority of cases of hepatitis in children, had received any of the COVID-19 vaccinesmaking the link between the disease and these vaccines impossible.
What should parents do?
It is important to remember that although this is a concerning condition, it has so far only affected a small number of children worldwide. If a child has any of the above symptoms, particularly if they are persistent or unexplained, parents should see a doctor.
Children should be encouraged to engage in simple hygiene activities, such as regular hand washing, especially after using the bathroom or before eating. Children experiencing symptoms of a gastrointestinal infection, such as vomiting and diarrhea, should stay home and not return to school or day care until 48 hours after symptoms have resolved.
Simple respiratory hygiene during viral upper respiratory tract infections is also important; children should be shown how to blow or wipe their nose with a tissue, which should then be placed in a container and the child should then wash their hands.