How a rare, mysterious liver illness in children could be linked to COVID-19

Health officials are exploring why hundreds of children around the world – including some in Canada – are being affected by mysterious liver damage.

There have been at least 10 confirmed cases of acute severe hepatitis in Canada. One of those was in Québec. 

More than 20 countries have reported cases, with the largest numbers coming from the U.K. and the U.S.

A small number of cases have been fatal.

And there seem to be more questions than answers about the disease that a pediatric infectious disease specialist in Montreal is calling “a relatively rare event.”

Dr. Jesse Papenburg of the Montreal Children’s Hospital is monitoring the spread of acute severe hepatitis in children.

“First, it’s important to understand that all of these children have been investigated for the usual suspects of hepatitis,” said Papenburg. “So hepatitis A, B, C and E, and have come up negative. There are other viruses that occasionally can cause hepatitis, and so far we haven’t seen those viruses come up as being linked to these cases.”

Hepatitis is an inflammation of the liver. Depending on the cause, the Public Health Agency of Canada says the disease can be sudden and progress to liver failure over a few days to weeks.

Since April, the World Health Organization (WHO) has reported an increase of the disease.

Possible culprit: adenovirus 41

The cause of acute severe hepatitis is not known at the moment, but many hypotheses are being explored. One of those is adenovirus 41, a common stomach bug that typically causes cold or flu-like illness or gastroenteritis.

More than half of the U.S. cases, for instance, tested positive for adenovirus, of which there are dozens of varieties. In a small number of specimens tested to see what kind of adenovirus was present, adenovirus 41 came up every time.

Many adenoviruses are associated with common cold symptoms, such as fever, sore throat and pink eye. Some versions – including adenovirus 41 – can trigger other problems, including inflammation in the stomach and intestines.

Adenoviruses previously have been linked to hepatitis in children, but mostly in kids with weakened immune systems.

Papenburg says the symptoms of acute severe hepatitis in children can be wide ranging.

“It could be loss of appetite with some fever, nausea, vomiting, diarrhea often associated with it as well,” he said. “But the worrying signs would be if you see signs of jaundice, that is to say, a yellowing of the skin, a yellowing of the whites of the eyes, a dark-coloured urine and pale stools accompanied by lethargy and generally not doing well.

“These are the warning signs that would warrant medical attention.”

Could hepatitis and COVID-19 be linked?

According to the WHO, side effects from the COVID-19 vaccines are not suspected since most children affected were too young and not inoculated.

However COVID-19 itself may be behind the disease, according to a report from medRxiv.

The report suggests children are at an increased risk for liver dysfunction after having COVID.

Only 10-15 per cent of the children with the mysterious hepatitis had COVID-19, according to nasal swab tests given when they checked into a hospital, health officials say.

But investigators are wondering about previous coronavirus infections: if particles lurking in the gut are somehow playing a role.

Experts say, though it’s only a hypothesis, precautions like wearing a mask should be taken.

“You have this outbreak of hepatitis that is life-threatening and for which we don’t entirely know what’s going on, but it could very well be related to COVID in unvaccinated children,” said Dr. Donald Vinh, an infectious diseases specialist with the McGill University Health Centre. “You kind of put the pieces together and say maybe the masks should be kept in place, at least in indoor activities, including schools. And that’s my concern.”

Of the at least 10 cases in Canada, three were reported in Alberta, two in Manitoba, four in Ontario and one in Québec .

The children range in age from one to 13 years old. Every single one was hospitalized, with two of them requiring a liver transplant.

As of May 20, the CDC confirmed six deaths linked to acute severe hepatitis.

No deaths have been confirmed in Canada.

“Right now, we’re really at the stage where public-health officials across the world are trying to collect as much data as possible, in as systematic a way as possible, to try and figure out what it might be, the potential causes of this severe but thankfully very rare manifestation,” said Dr. Papenburg.