Hepatitis B Screening
Hepatitis B virus (HBV) antigens are proteins that appear in different areas of the virus.The basic blood test for hepatitis B consists of three screening tests: a hepatitis B surface antigen test, which determines whether a person currently has the infection; a hepatitis B core antibody test, which determines whether a person has ever been infected; and a hepatitis B surface antibody test, which determines whether a person has cleared the virus after infection, or has been vaccinated and is now immune to future infections.The body's immune response produces antibodies tailored to each type of antigen (surface antibody, core antibody, and e antibody), which can also be detected from a blood test.The hepatitis B core antibody screening test detects the presence of antibodies to the HBV core antigen.The hepatitis B surface antibody screening test detects the presence of antibodies the immune system produces to attack the virus.A positive hepatitis B surface antibody screening test means the person has lifetime immunity from hepatitis B (the Centers for Disease Control and Prevention [CDC], 2009).The screening test for hepatitis B surface antigens detects the presence of HBV in the blood.The antigens are detectable 4-10 weeks after exposure to HBV.Is the person currently infected with HBV?These are described below.