Hepatitis B Virus Tests

Test Overview

Hepatitis B tests are blood tests that show whether you have an active hepatitis B infection. The tests can also show if you had the infection in the past.

The tests look for different signs of infection:

• Antigens, which are made by bacteria or viruses.
• Antibodies, which are made by the body to fight infection.
• Hepatitis B DNA, which is the virus's genetic material.

Hepatitis antibodies can take weeks or months to develop. So an infected person may test negative early in the infection.

Most common tests

The most common tests are:

• Hepatitis B surface antigen. This antigen is the earliest sign of an active hepatitis B infection. It may be present before symptoms occur.
• Hepatitis B surface antibody. The presence of this antibody means that the infection is at the end of its active stage and you are no longer contagious. You can't pass the virus to others.
• Hepatitis B e-antigen. This antigen is only present during an active hepatitis B infection.
• Hepatitis B DNA testing. A high level of this DNA means that the virus is multiplying in your body and you are very contagious.

Other tests

These tests are not done as often:

• Hepatitis B core antibody. This antibody appears about 1 month after the start of an active infection. It can be found in people who had an infection in the past. It is also present in those with long-term, or chronic, hepatitis B.
• Hepatitis B core antibody IgM. This antibody shows that a hepatitis B infection has occurred within the last 6 months. It can also mean that a chronic hepatitis B infection has flared up again.
• Hepatitis B e-antibody. This antibody shows that the active stage of a hepatitis B infection is almost over, and your risk of spreading the virus is a lot lower.
• Hepatitis D antibody. This test shows whether you're infected with the hepatitis D virus. This infection occurs only in people who are already infected with hepatitis B. It's rare in the United States and Canada, except among people who inject illegal drugs and those who are often exposed to blood products.