Hepatitis B surface Antigen (HBsAg)
Hepatitis B virus has a surface antigen, i.e. a protein that triggers the production of antibodies after an infection in the body. Hepatitis B surface Antigen (HBsAg) appears within six weeks to sixteen weeks following exposure and disappears within four to eight weeks after the symptoms manifest in an acute infection. If HBsAg persists up to six months or more – it is suggestive of a chronic hepatitis B infection or a chronic carrier state and requires immediate medical attention.
Why is the test ordered?
The test is ordered to screen for the presence of the hepatitis B virus in the blood.
When is the test recommended?
Hepatitis B surface antigen test is useful for the detection of acute, recent or chronic hepatitis B infection.
How is the sample collected?
A blood sample is collected from a vein in the arm.
How to prepare for the test?
No special preparation required for the HBsAg test.