At least three cases of unusual, severe hepatitis in kids are under investigation in a new state: Illinois. Eleven cases of the liver disease, under investigation by the Centers for Disease Control and Prevention and World Health Organization, have already been reported in Alabama (nine cases) and North Carolina (two cases).
The children in Illinois are all under age 10. One required a liver transplant.
At WHO's last count, there were 169 cases of the severe hepatitis across 12 countries in kids 1 month to 16 years old. Seventeen have needed liver transplants, and at least one has died.
The cases are unusual because the viruses that typically cause hepatitis, aka inflammation of the liver, have been ruled out. Health officials in the U.S. and U.K., where most of the global cases have been identified, are investigating adenovirus as a possible cause, but the connection is far from confirmed.
Adenoviruses are common, causing respiratory and gastrointestinal symptoms. They do not typically cause hepatitis in healthy children.
A recent report from health officials in the U.K. said 75% of children with the severe hepatitis who were tested for adenovirus were positive. What's more, adenovirus cases in the country dropped during the pandemic but have recently risen to above pre-pandemic levels. Still, it's not clear how adenovirus might lead to severe hepatitis, so health officials are investigating a few possible causes, such as a novel strain of adenovirus, kids' increased susceptibility due to reduced exposure to the outside world during the pandemic, or an undiscovered co-infection or toxin.
The Illinois cases were also "potentially linked to a strain of adenovirus," according to the state's public health department. Two were identified in suburban Chicago and one in Western Illinois.
An Illinois case under investigation involved a 4-year-old boy with hepatitis who tested positive for adenovirus at a local hospital, according to NBC Chicago.
"We followed him in the hospital for three, four days and actually got a liver biopsy to kind of see how bad the injury was on his liver and it was pretty severe,” Dr. Vincent Biank, a pediatric gastroenterologist at Advocate Children’s Hospital in Park Ridge, Illinois, told NBC Chicago.
The child did not require a liver transplant and was discharged last week.
According to WHO, the “vast majority” of affected children did not receive the COVID-19 vaccine, so the WHO does not believe it has anything to do with side effects from the vaccine.