The number of children in the UK confirmed to have been affected by a mystery hepatitis outbreak has risen to 108.
The UK Health Security Agency (UKHSA) announced it had identified a further 34 cases on Thursday, in addition to the 74 reported last week.
Cases have also been discovered in the US state of Alabama, as well as in Denmark, Ireland, the Netherlands, Spain and Israel.
Here is everything you need to know.
What is causing the hepatitis outbreak?
Experts are not yet certain what is behind the outbreak but any link to existing hepatitis viruses has been ruled out.
Dr Meera Chand, director of clinical and emerging infections at UKHSA, said officials are working to “investigate a wide range of possible factors which may be causing children to be admitted to hospital with liver inflammation known as hepatitis”.
One possibility being examined is that the outbreak is linked to adenovirus infection.
Adenovirus is a common-cold virus, which can cause more serious symptoms, including gastrointestinal illness in young children.
Cases of adenovirus in children were far lower than normal in 2020 and remained below the average in 2021.
Experts believe that it is possible that children’s immunity has been lowered by a lack of exposure to the virus due to Covid lockdowns, and this has led to some experiencing worse symptoms after now being exposed.
A UKHSA spokesperson said: “One of a number of potential causes under investigation is that a group of viruses called adenoviruses may be causing the illnesses.
“However, other possible causes are also being actively investigated, including Covid-19, other infections or environmental causes.”
What is hepatitis?
According to the NHS, hepatitis describes inflammation of the liver.
Typically, it is the result of a viral infection or liver damage caused by drinking alcohol.
There are multiple types of hepatitis (A to E, as well as alcoholic hepatitis and autoimmune hepatitis), some of which will pass without any 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.
Short-term (acute) hepatitis often has no noticeable symptoms, so you may not realize you have it.
If symptoms do develop, they can include:
- Muscle and joint pain
- high temperature
- Feeling and being sick
- Feeling unusually tired all the time
- General sense of feeling unwell
- loss of appetite
- tummy pain
- dark urine
- Pale, grey-coloured poo
- itchy skin
- Yellowing of the eyes and skin (jaundice)
Should I be worried?
Experts have called the recent unusual hepatitis outbreak, and there are concerns, but at the moment it is only affecting a minute number of children.
There are currently 108 infections in the UK, which is roughly 16 per million children under the age of 10.
None of the children have died from the virus, but eight have received liver transplants.
Professor Sheila Bird, former program leader at the MRC biostatistics unit at the University of Cambridge, said the proportion of children needing liver transplants, while a minority, was still “remarkable”.
Parents have been advised to look out for the symptoms of hepatitis listed above.
Dr Chand said: “Normal hygiene measures such as thorough handwashing (including supervising children) and good thorough respiratory hygiene, help to reduce the spread of many common infections, including adenoviruses.
“We are also calling on parents and guardians, to be alert to the signs of hepatitis (including jaundice) and to contact a healthcare professional if they are concerned.”
Dr Zania Stamataki, associate professor in viral immunology at the Center for Liver and Gastrointestinal Research at the University of Birmingham, said: “Liver inflammation (known as hepatitis) caused by adenovirus is uncommon in the young, with the exception of immunocompromised children.
“The rising incidence of children with sudden onset hepatitis is unusual and worrying. If an adenovirus is to blame, this could be a new variant of adenovirus that may cause liver injury in children with naive/immature immune systems. But we need to know more to be sure.
“Alternatively, if adenovirus is the culprit for hepatitis in children that are otherwise well, we ought to look for other infections and environmental causes that could exacerbate adenoviral inflammation.”