Understanding Your Test Results
Understanding your hepatitis B blood tests can be confusing. It is important to talk to your health care provider, so you understand your test results and your hepatitis B status. Are you infected? Protected? Or at risk? The Hepatitis B Panel of blood tests includes 3 tests and all three results must be known to confirm your status.
Below is a chart with the most common explanation of the test results, but unusual test results can occur. Please note that this chart is not intended as medical advice, so be sure to talk to your health care provider for a full explanation and obtain a printed copy of your test results. In some cases, a person may be referred to a liver specialist for further evaluation.
The following graphic from the U.S. Centers for Disease Control and Prevention (CDC) represents the typical course of an acute hepatitis B infection from first exposure to recovery.
Source: Reprinted from Centers for Disease Control and Prevention Recommendations for Identification and Public Health Management of Persons with Chronic Hepatitis B Virus Infection
More Detailed Information About Hepatitis B Blood Tests
During an acute infection, it can take up to six months for a person to get rid of the hepatitis B virus from their blood. So, it can take up to six months for a hepatitis B blood test to show whether a person has recovered from an acute infection or has developed a chronic infection.
According to the CDC, a hepatitis B blood test result (or serologic marker) varies depending on whether the infection is a new (acute) infection or a chronic infection.
- HBsAg (hepatitis B surface antigen) is the first serologic marker to appear in a new acute infection, which can be detected as early as 1 week and as late as 9 weeks (range: 6-60 days), with an average of one month after exposure to the hepatitis B virus (HBV)[1].
> HBsAg is detectable for a variable amount of time, along with the HBV DNA, though about 50% of persons newly infected will test HBsAg and HBV DNA negative 7 weeks after symptoms disappear.
> Acutely infected persons who spontaneously recover from an infection will generally test negative for HBsAg and negative for HBV DNA about 15 weeks after the appearance of symptoms.
- Anti-HBs or HBsAb (hepatitis B surface antibody) – This becomes detectable on a blood test after the disappearance of HBsAg in persons who are able to get rid of the virus (recover from an acute infection). The presence of anti-HBs following a new acute infection generally indicates recovery and a person is then protected (or “immune”) from re-infection with hepatitis B.
- Anti-HBc or HBcAb total (hepatitis B core antibody) – this blood test remains positive indefinitely as a marker of past HBV infection.
- HBeAg (hepatitis B e-antigen) is generally detectable in patients with a new acute infection but can also be present in a chronic infection. The presence of HBeAg is associated with higher HBV DNA levels, thus, increased infectiousness.
- IgM anti-HBc – a positive blood test result indicates a person has a new acute hepatitis B infection. IgM anti-HBc is generally detectable at the time symptoms appear and declines to sub-detectable levels within 6 - 9 months.
- Note: An acute exacerbation (or liver flare) in a chronic HBV infection can also result in a positive anti-HBc IgM test result. Follow-up testing after 6 months is required in this case.
- IgG anti-HBc – this blood test remains positive indefinitely as a marker of past HBV infection.