What is Hepatitis of Unknown Aetiology? 

Hepatitis is an inflammation of the liver. Hepatitis infection is most often caused by the hepatitis virus, which has five main strains referred to as types A, B, C, D and E. These strains spread in different ways and cause different types of illness. 

How Hepatitis spreads depends on the virus strain. Hepatitis A and E are usually caused by ingesting contaminated food or water. Hepatitis B, C and D infections are generally caused when infected body fluids enter the body through penetration of the skin.  

Acute, severe hepatitis of unknown origin refers to severe hepatitis cases that are not caused by any of the five virus strains. Some children who have become sick with acute, severe hepatitis of unknown origin are infected with a virus called adenovirus type 41 (which causes acute gastroenteritis). However, it is unknown if this virus is causing the recent hepatitis cases.