“We know that all the measures we took to reduce the transmission of SARS-CoV-2 meant that there was a much reduced circulation of seasonal viruses,” said Dr. Antonia Ho, a clinical senior lecturer at the MRC-University of Glasgow Centre. for Virus Research, and a co-author of one of two hepatitis studies published on Monday.
“Now that there are children back in school, there is inevitably a balance that needs to be restored and many seasonal viruses are being transmitted and circulating beyond what we would normally expect from them and this big wave [of adenovirus infections] is not typical for this time of year.
“So yes, in a sense, the pandemic [was involved] for all sorts of reasons. We are now seeing different types of circulation that may have contributed to this type of hepatitis with AAV2.”
AAV2 can infect cells, but can’t replicate and cause damage and must piggyback on another virus to do so. It has never before been shown to be harmful to human health.
However, academics found signs that AAV2 and adenoviruses could somehow work together to cause hepatitis.
Exactly how this damages the liver remains unknown, and experts don’t yet know whether AAV2 is the harmful agent or whether it’s the common cold bacteria.
Academics from the University of Glasgow teamed up with Public Health Scotland (PHS) and looked in detail at nine children who had the condition.
AAV2/cold link has ‘probably happened before’
They found adenovirus in six of the nine children and AAV2 in all of them. A separate study, conducted in part by the UKHSA, found that 94 percent of unexplained hepatitis patients had AAV2 in their systems. In the general population, the virus is found in only six percent of people.
Unexplained cases of hepatitis have always been seen in children, but this year’s numbers were smaller than what had been seen in years past and researchers believe the AAV2/cold connection has always been present, but small numbers of cases have made it impossible to establish the link. to see.
“My feeling is that this has probably happened before,” said Professor Emma Thomson, a clinical professor at the MRC-University of Glasgow Center for Virus Research.
“I think what happened is that these things may have trickled in and it would have been very difficult for us to see them in the past.
“Because there have been some changes in the seasonal trends of these viruses, we’ve seen a small collection of cases at once, and so we picked them up.”
Official data on the hepatitis outbreak are expected by the UKHSA later this week, but Dr. Meera Chand, the director of clinical and emerging infections at UKHSA, said the forthcoming data will show a “very marked decline” in the number of cases, with the weekly count now “nearly back to baseline”.
The two papers are published as pre-prints prior to peer review.