Since the beginning of the year, at least 111 children in the UK have been identified with acute hepatitis that does not appear to be from the group of hepatitis viruses as the most likely cause. Several cases have been reported in the United States and other countries around the world.
Nearly three-quarters of the 53 children tested for adenoviruses in the UK Positively returned. On the other hand, the virus that causes Covid-19 was found in only a sixth of the children tested – in line with levels of community transmission in the UK.
Adenoviruses make up a large family of viruses that can spread from person to person, causing a range of illnesses including the common cold and gastroenteritis. It is rarely reported as a cause of acute hepatitis in otherwise healthy people.
But these hepatitis cases come as the spread of adenovirus has escalated in recent months, along with other common viruses that have surged with the end of Covid-19 prevention measures and behaviors that have kept most germs at bay.
After dropping dramatically during the pandemic, documented cases of adenovirus have turned back and are now at levels higher than what the UK experienced before Covid-19.
Although investigations are on adenovirus, it is still not clear how it can cause hepatitis. Experts say the virus may be just one factor that leads to these cases when it occurs along with something else.
Experts say another possibility may be timing. Children who usually had mild symptoms as children can have more severe reactions to viruses now that they are older.
UK scientists are eyeing a particular type of adenovirus due to blood sample data, but will need to look at its genetic makeup as confirmation.
According to the UK’s Health Security Agency, cases have been mostly of children under 5, with an average age of 3, and only “a small number of children over the age of 10” are being investigated. Dozens have recovered and no deaths have been reported in the UK, but 10 children have required liver transplants.
CNN’s Brenda Goodman contributed to this report.