Scientists baffle about the link between the Covid pandemic and hepatitis cases in children 2022-04-28 23:02:13


After two years of researching data to explain the coronavirus, public health officials are now seeking to understand the unexpected rise in hepatitis cases in otherwise healthy children that are appearing in a growing number of countries.

Canada and Japan this week joined more than a dozen other countries in reporting the outbreak as key health agencies, including the World Health Organization and the European Center for Disease Control and Prevention, Investigations started In approximately 200 known cases.

Theories about the origin of the mysterious disease, which is linked to acute hepatitis and has led to at least 17 children needing transplants, have spread since UK health authorities first sounded the alarm in early April. One child has died so far, according to the World Health Organization.

Many scientists searching for the causes of the outbreak have focused on the role the coronavirus pandemic plays. Experts hypothesized that the illness could be related to reduced immunity to adenovirus, a cause of the common cold, due to two years of pandemic-related restrictions, the after-effects of coronavirus infection or even a mutated form of one of those viruses.

“Whatever theory you subscribe to, this must stem from the massive public health event of the past two years,” said Alistair Sutcliffe, professor of general pediatrics at University College London. “It’s too much of a coincidence – either it’s a decrease in immunity to the adenovirus or the adenovirus is cooperating with Covid to cause hepatitis, but the epidemic has to play a role.”

Northern Hemisphere countries have recorded a rise in the number of common viruses – such as adenovirus, rhinovirus and chicken pox – since anti-epidemic measures were eased this winter, while also recording record infection rates of Covid disease.

It’s possible that the “immunity whitelist” left by low social mixing, with countries shutting down and schools shutting down, could make the effects of the adenovirus “more devastating,” said Will Irving, professor of virology at the University of Nottingham.

“It may be important early in life to meet a whole host of viruses and treat yourself, and that didn’t happen,” Irving said.

But scientists cautioned against jumping to conclusions.

Adenovirus – a group of viruses usually associated with symptoms such as a persistent cough, conjunctivitis or diarrhea – sometimes causes hepatitis but never causes hepatitis in healthy children.

“People speculate until their face turns blue, but all we have is a pile of correlations and there’s no definitive cause,” said Isaac Bogoch, MD, associate professor of medicine at the University of Toronto in Canada.

With around three-fifths of known cases in the UK, UK scientists are leading the way in investigating the disease. Of the 53 children in the UK tested for adenovirus, 40 came back with positive results. But 16 per cent of more than 100 cases in the UK have also tested positive for Covid-19 on admission, compared to a community infection rate of 5 to 8 per cent over the same period.

“There is some clues but there is still a lot of scientific investigative work to be done,” said Deirdre Kelly, professor of pediatric hepatology at Birmingham Hospital for Women and Children, who has treated the largest group of patients.

Philippa Easterbrook, a medical expert with the World Health Organization’s global program to combat HIV, hepatitis and sexually transmitted diseases, said at a press conference this week that the idea that the adenovirus may have led to more serious infections because it was suppressed during the lockdown was “an assessment Interesting for “the data but really needs to follow up with further investigations”.

Covid-19 vaccines have been ruled out as a possible cause, because the disease mainly affects children under the age of 10 – few of whom have received vaccinations.

The first cases of mysterious hepatitis were recorded in the US state of Alabama between November 2021 and February of this year. Five of the nine children tested positive for adenovirus, while none of them showed signs of current or previous infection with Covid. Last week, the US Centers for Disease Control and Prevention issued an alert about the disease, and seven states are now investigating potential cases.

“When . . . was presented to me, and I said I had never seen a group like this in my career,” said Dr. Karen Landers, the chief medical officer of the Alabama Department of Health, who has worked in public health for more than four decades.

Professor Geoffrey Lazarus, head of the Health Systems Research Group at the Barcelona Institute for Global Health, said the “long list” of symptoms associated with Covid-19 suggested the possibility of a previous infection with the coronavirus. There was a whole host of Covid symptoms. I wouldn’t be entirely surprised if an extra one was added,” he said.

Experts believe that a previous infection with Covid-19 can weaken the immune system, leading to a more severe reaction to the adenovirus.

In the UK, genetic sequencing analysis is performed on adenovirus samples from patients to determine if the virus has taken on mutations that can lead to hepatitis. Covid antibody testing is also underway.

However, Lazarus cautioned some experts would “jump the gun on their ideas about Covid restrictions.” “Comment before science. Let’s give science time to catch up.”