DNA Explainer: What we know so far about mystery liver disease affecting children

Even as the world battles with the Covid-19 pandemic, various diseases have been emerging from time to time from parts of the world. Now, a mysterious liver disease is been detected in children in some parts of the United States and Europe, mostly the United Kingdom. 

While in UK at least 74 cases of mysterious liver disease has been reported, the United States reported 9 similar cases, all from Alabama state. Spain, Denmark, the Netherlands and Ireland are also investigating a few similar cases. So far, no deaths have been reported due to the disease.

The mysterious liver disease is an emerging cause of concern as the illness is not being explained by known causes. This mystery liver illness attacking only children has been brought to the notice of the World Health Organisation (WHO) early this month.

Read | DNA Explainer: How a degenerative mystery illness is affecting young adults

What is this mysterious liver disease?

Children between the age of 1 to 6 years old have been the target of the mysterious liver disease specially in the US and the UK.

WHO first became aware of the unusual illnesses early this month, when they learned of 10 children in Scotland with liver problems.

One child got sick in January and the nine others in March. All became severely ill and were diagnosed with hepatitis in the hospital.

Symptoms of this illness are similar to general liver diseases like hepatitis or liver inflammation but the cause remains unknown.

Jaundice, diarrhoea and abdominal pain have been reported in patients infected with the mysterious liver disease.

The liver processes nutrients, filters the blood and fights infections. Hepatitis disease can be life-threatening if left untreated.

British health officials have identified at least 64 more cases. None died of it, but six needed liver transplants, the WHO said Friday.

Laboratory testing has ruled out the hepatitis type A, B, C and E viruses that usually cause such illnesses.

Officials say they are not aware of international travel or other factors that might have put the kids at risk of the unknown disease.

The illness has been so far reported to be severe. Reports say it might be related to some kind of virus usually associated with colds.

Some of the European children tested positive for adenovirus, and some tested positive for Covid-19, the WHO said.

None of the Alabama cases had any underlying health conditions that would seem to put them at risk for liver illness, health officials said.

Symptoms to look out for

Dark urine

Pale faeces

Jaundice (yellowing of eyes and skin)

Itchy skin

Nausea and vomiting

Lethargy

Stomach pain

High temperature

Possible causes of the outbreak

According to scientists in Scotland, the leading hypothesis is that the liver damage is being caused by an adenovirus, a large group of viruses that circulate widely and are often linked to respiratory and eye infections. Alabama officials are exploring a link to one particular version, adenovirus 41, that is normally associated with gut inflammation.

Adenoviruses previously have been linked to hepatitis in children, but mostly in kids with weakened immune systems. There are dozens of adenoviruses, many of them associated with cold-like symptoms, fever, sore throat and pink eye. But some versions can trigger other problems, including inflammation in the stomach and intestines.

Alternatively, there is thought it may be as a result of a Covid-19 infection or even a new, undetected variant. "A novel or yet undetected virus also cannot be ruled out at this time," officials wrote in the report.

Investigators have also ruled out a food, drink or personal care product that may be causing the illness. Toxic exposure is also unlikely.