Hepatitis viruses are infectious agents that can infect liver and cause 
inflammation. The infection triggers immune response against infected cells that 
leads to the destruction of hepatic cells. This destruction has two 
consequences: leaking ALT and AST liver enzymes which increases during the 
course of disease and accumulation of bilirubin- a red pigmented compound 
released from dead red cells- which causes the yellow coloration of eyes and 
skin. These viruses transmit through diverse routes i.e. blood transfusion, 
sexual contacts and consuming water or food contaminated by feces. Enteric 
hepatitis viruses use the latter route for transmission; hence their outbreaks 
are more common in underdeveloped countries. There are currently two 
distinguished enteric hepatitis viruses, hepatitis A and hepatitis E. These 
viruses belong to different family of viruses and their epidemiological 
characteristics are different. These infections can be diagnosed by an ELISA for 
IgM antibody. A vaccine has been developed in last decade of twentieth century 
for hepatitis A virus, which is administered mostly in the developed world i.e. 
U.S and Japan. Treatment for these infections is mostly supportive; however, in 
the case of fulminant hepatitis the liver transplantation might be necessary.