CDC concerned with over 100 unexplained cases of Hepatitis in kids

(KYMA, KECY/ CNN) - Health officials are worried about more than 100 cases of severe and unexplained Hepatitis in children.

The Centers for Disease Control and Prevention has reported 109 cases in 25 states. So far, five kids have died and 14% needed liver transplants. Almost all of them have had to be hospitalized.

It's still a mystery what is causing the disease and investigators say there may not be a single cause.

Hepatitis is a general term used to describe any swelling of the liver. Viruses, toxins, and autoimmune diseases are among a variety of things that can lead to it.

One of those viruses is Adenovirus -- which researchers detected in more than 50% of the cases. However, in many of those instances, the virus was only detected in the blood, and not in liver tissue as would be expected.

Adenovirus is also common and doesn't usually lead to Hepatitis in otherwise healthy children.