(NewsNation) — A child has died in connection with a mysterious liver disease outbreak affecting children in Europe and the United States, the World Health Organization reported Saturday in a news release.

WHO didn’t say where the death occurred.

The first cases were reported in Britain, where 114 children fell ill.

The children’s ages where the cases were reported spanned from one month to 16 years old. A total of 17 cases were in children with liver transplants.

“It is not yet clear if there has been an increase in hepatitis cases, or an increase in awareness of hepatitis cases that occur at the expected rate but go undetected,” WHO said in the news release Saturday.

Additionally, the U.N. health agency says there have been at least 169 cases of “acute hepatitis of unknown origin” from a dozen countries.

Experts say the cases may be linked to a virus commonly associated with colds, but further research is ongoing.

“While adenovirus is a possible hypothesis, investigations are ongoing for the causative agent,” WHO said, noting that the virus has been detected in at least 74 of the cases. At least 20 of the children tested positive for the coronavirus.

Adenovirus, a common group of viruses, is now circulating in children at higher than average levels after dropping to unusually low levels during the pandemic. One avenue of inquiry being explored is that the outbreak may be linked to a surge in common viral infections after COVID-19 restrictions were phased out. Children who weren’t exposed to adenovirus over the last two years may now be getting hit harder when they are exposed to the viruses.

“Information gathered through our investigations increasingly suggests that this rise in sudden onset hepatitis in children is linked to adenovirus infection,” said Dr Meera Chand, director of clinical and emerging infections at UKHSA. “However, we are thoroughly investigating other potential causes.”

Chand presented the British data Monday during an emergency session of the European Congress of Clinical Microbiology & Infectious Diseases in Lisbon.

The usual viruses that cause infectious liver inflammation — hepatitis A to E — weren’t detected in any of the 111 cases being investigated in the U.K. The victims suffered symptoms such as jaundice, diarrhea and abdominal pain.

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

There are dozens of adenoviruses, many associated with cold-like symptoms, fever, sore throat and pink eye.

So far, at least 169 cases have been reported worldwide.

In the U.S., at least nine cases have been reported in Alabama in children 1 to 6 years old — two of them becoming so ill they needed a liver transplant.

An additional two cases have also been reported in North Carolina.

NewsNation’s “Rush Hour” caught up with Dr. Anthony Harris on Monday evening to address the severity of the illness for kids in the U.S. He assures there’s no reason to panic.

“At this point, there’s still no dramatic concern that we should be carrying in regards this being a new pandemic. What we have seen thus far is that it’s still very likely that this underlying condition of the liver called hepatitis is caused by something we have known, which is adenovirus, to cause hepatitis in children and in, in adults as well,” Harris said.

Harris is the founder of Hfit Health and told the program that, so far, research into these infections has found neither COVID-19 nor the COVID vaccines have anything to do with these cases.

Instead, he says, they’re signs pointing to a virus not usually associated with hepatitis: adenovirus type 41. According to The Centers for Disease Control and Prevention, this particular type of virus is known to cause symptoms much like the common cold and vomiting and diarrhea in kids.

U.K. public health officials have ruled out any links to COVID-19 vaccines, saying none of the affected children was vaccinated.