Hepatitis in children: Scientists have found a possible cause for the mysterious outbreak

Between April and July this year, 1,010 cases of serious hepatitis without an explainable cause have been reported in children in more than 35 countries. Almost half of those cases have been in Europe, with more than a quarter in the UK.

Usually, childhood hepatitis is caused by infection with one of the hepatitis viruses (such as hepatitis A or Hepatitis C). But although the children had high levels of hepatitis markers in their blood, no trace of the hepatitis virus has been detected in these children, or in any related cases since.

Buy now | Our best subscription plan now has a special price

Initial investigations have found a potential link between adenovirus infection and these cases of hepatitis. Adenoviruses are very common viral infections, especially in children. They usually cause infections such as mild colds, pink eyes (conjunctivitis) or stomach problems. However, if they reach the liver, they can, in rare cases, cause hepatitis.

However, given how common adenoviruses are in children – and because they rarely cause hepatitis in healthy people – it was hard to say this was the likely cause.

A new study suggests that the wave of severe hepatitis cases seen in children could be the result of three The factors working together: adenovirus, adeno-associated virus 2 (AAV2) and an underlying genetic predisposition to disease.

A potential cause appears

In a pre-print study (meaning it hasn’t yet been reviewed by other scientists), a team of researchers looked at nine of the original hepatitis cases in April and performed a wide range of tests , seeking to find new or previously undetected viruses. or genetic factors that may have caused hepatitis in children.

The team discovered that all nine children had been infected with adeno-associated virus 2. They then compared their results with 13 healthy children and 12 children who had had adenovirus infections but no hepatitis. Adeno-associated virus 2 was not detected in any of these children. This was a strong indicator that AAV2 was a cause of these mystery cases of hepatitis.

Adeno-associated virus 2 belongs to a group of viruses called Dependoparvovirus that infects both humans and some primates. But what is particularly interesting about AAV2 is that in order to infect the host, another virus must also infect the host at the same time. It uses this helper virus to replicate inside human cells. The most common helper viruses of AAV2 are adenovirus and herpes virus.

The researchers found that six of the nine patients they examined had adenovirus, while three showed signs of a herpes virus. It is therefore likely that this hepatitis was caused by a combination of AAV2 and one of these helper viruses.

Immune systems and infections

But AAV2 and infections such as adenovirus and herpes virus are fairly common in children, and most children infected with these do not develop hepatitis. This means that there must be an additional factor at play here, perhaps even at the genetic level.

The team of researchers then analyzed the children’s genomes to look for immune system markers called human leukocyte antigens. Immune system cells use human leukocyte antigens to detect and engulf other viruses and pathogens.

This then sends a signal to other immune cells to arrive and destroy the pathogen. There are many different types of human leukocyte antigens, and depending on why a person has the condition, they can determine which infections they are more susceptible to.

The researchers found that eight of the nine children had a higher genetic prevalence of a certain type of human leukocyte antigen, which may have increased their likelihood of getting symptoms of hepatitis from these viral infections. This type is also more common in people of European descent, which may further explain why these cases of hepatitis have mainly been seen in Europe.

Although it is clear from this study that a combination of factors may explain the sudden and severe cases of hepatitis observed in children, the study itself was small and was only conducted on participants in Scotland. A much larger, peer-reviewed study will need to be done to fully understand the exact link and how best to protect children in the future.

Another factor that could have played into this was COVID-19[feminine] restrictions, which meant that many children were not exposed to these viruses and did not develop immunity at the age they would normally be. This meant that when restrictions were lifted, children were suddenly exposed to these viruses, which overwhelmed their immune systems which were unprepared to deal with them.

However, more research is needed to determine if it really played a role in cases of severe hepatitis. But if it is found to be a cause, it is likely that we will see fewer and fewer cases of hepatitis in children as the months have passed since the last confinement.

For all the latest parenting news, download the Indian Express app.

Leave a Comment