This test is used to determine the presence of active Hepatitis B infection by measuring the amount of HepB envelop antigen expressed on the of virus. It is a preliminary test to detect the infection at earliest possible stage. A positive HepB envelop antigen test requires further testing to determine the level of infection in the body.Hepatitis B virus spreads mainly through body fluids or unsafe sexual intercourse. This Infection is curable by antiviral medication but in some cases uncontrolled levels of HepB Virus can lead to chronic hepatitis infection and liver cirrhosis. Immunocompromised patients and infants are more prone to develop severe symptoms of chronic hepatitis.