Commonly Asked Questions
Hepatitis B testing is available from many sources throughout the United States. Our Hep B United partners provide testing in cities throughout the U.S. Visit http://hepbunited.org/local-campaigns to learn more about local coalitions near you and upcoming screenings.
The U.S. Centers for Disease Control and Prevention also maintains a database of testing centers, searchable by zip code, at https://gettested.cdc.gov/.
There is a simple hepatitis B blood test that your doctor or health clinic can order called the “Hepatitis B Panel”. Only one blood sample is needed, but there are 3 parts to the hepatitis B panel. The health provider may ask to check your blood again six months after your first visit to confirm your hepatitis B status. If you think you have been recently infected with hepatitis B, it may take up to nine weeks before the virus will be detected in your blood (this refers to the “incubation” period for the virus to appear after an exposure or the “window period.”) .
Understanding your hepatitis B blood test results can be confusing, so be sure to discuss your test results with the health provider - do you have a new infection, have you recovered from a past infection, or do you have a chronic infection?
The hepatitis B blood panel requires only one blood sample but includes three tests:
- HBsAg (hepatitis B surface antigen)
- Anti-HBs or HBsAb (hepatitis B surface antibody)
- anti-HBc or HBcAb (hepatitis B core antibody)
The results of all 3 blood test results are needed in order to make a diagnosis. Be sure to request a printed copy of your blood tests so that you fully understand which tests are positive or negative, and what your hepatitis B status is.
This tests for the presence of the hepatitis B virus. A "positive" or "reactive" HBsAg test result means that the person is infected with the hepatitis B virus, which can be an "acute" or a "chronic" infection. Infected people can pass the virus on to others through their blood and infected bodily fluids.
A "positive" or "reactive" HBsAb (or anti-HBs) test result indicates that a person has successfully responded to the hepatitis B vaccine or has recovered from an acute hepatitis B infection. This result means that you are immune (or protected) against a future hepatitis B infection and you are not contagious. This test is not routinely included in blood bank screenings.
The HBcAb is part of the virus and it does not provide protection. A "positive" or "reactive" HBcAb (or anti-HBc) test result indicates a past or present infection, but it could also be a false positive. The interpretation of this test result depends on the results of the other two tests. Its appearance with the protective surface antibody (positive HBsAb or anti-HBs) indicates prior infection and recovery. For infected persons, it will usually appear with a positive HBsAg (meaning the virus is present). It is important to note the anti-HBc test results may be expressed as anti-HBc total, anti-HBc IgM, or anti-HBc IgG.
First, do not panic. The letter does not necessarily mean that you are infected with hepatitis B.
All donated blood is screened for hepatitis B. Many blood banks use the "hepatitis B core antibody" test to screen donor blood for potential hepatitis B infection (see “What is the hepatitis B core antibody?” above). This test can detect whether a person might have been exposed to the hepatitis B virus, but by itself this blood test doesn't tell whether the person is actually infected or not. This is why it is very important to see a health care provider or health clinic to get tested for the 3-part hepatitis B panel of blood tests for an accurate diagnosis.