“Typically, one won’t see ‘dramatic’ jaundice until the inflammation or dysfunction of the liver has progressed quite far already,” Dr. Weymann said.
What is causing the recent hepatitis clusters?
Hepatitis can have many causes, from autoimmune disease to side effects of certain medications. Most often, it is caused by one of the five hepatitis viruses (hepatitis A, B, C, D and E). Depending on the type, viral hepatitis can spread through contact with blood and other bodily fluids or fecal matter, or by consuming raw or undercooked meats. But viral hepatitis has been ruled out in the recent pediatric clusters in the United States and abroad.
Instead, the C.D.C. suspects that the adenovirus is causing the current cases, though health officials caution that the investigation is ongoing. There are more than 50 types of adenoviruses, which tend to cause mild illness, such as colds and fevers, pink eye or vomiting and diarrhea.
In Alabama, all nine children tested positive for adenovirus. And of the five cases that were genetically sequenced, all had adenovirus type 41, which typically causes vomiting and diarrhea. A majority of the affected children in Britain, though not all, tested positive for adenovirus as well.
“It’s interesting that we’re really only seeing this in children less than 10 years, meaning that most people over 10 have immunity to adenovirus, and that may be why this hepatitis is showing up in young children,” said Dr. Jennifer Lighter, a pediatric infectious diseases specialist and hospital epidemiologist with N.Y.U. Langone Health in New York City.
But doctors and health officials have known that adenovirus infection can cause liver inflammation. That’s not new. What is unusual is for otherwise healthy young children to become so suddenly ill, which is why public health officials are spreading the word and continuing to probe other possible underlying causes.
What can parents do?
Although health officials are not certain the adenovirus is causing the recent hepatitis clusters, parents can take steps to prevent transmission. Adenovirus spreads from person to person through respiratory droplets or through touching a surface with adenovirus on it. Children should be encouraged to wash their hands often and avoid touching their face and mouth to the extent it is possible — many of the same measures that help prevent the spread of Covid.
