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 in order 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 could be referred to a liver specialist for further evaluation.
More Detailed Information About Hepatitis B Blood Tests
An acute hepatitis B infection follows a relatively long incubation period - from 60 to 150 days with an average of 90 days. It can take up to six months, however, for a person to get rid of the hepatitis B virus. And it can take up to six months for a hepatitis B blood test to show whether as person has recovered from an acute infection or has become chronically infected .
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: Centers for Disease Control and Prevention Video
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, with an average of one month after exposure to the hepatitis B virus (HBV).
- HBsAg is detectable for a variable amount of time, along with the HBV DNA, though about 50% of persons will test HBsAg and HBV DNA negative 7 weeks after symptoms.
- All persons who spontaneously recover from an infection will 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 and avoid a chronic 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 (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; 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. So follow-up testing after 6 months is required.
- IgG anti-HBc – this blood test remains positive indefinitely as a marker of past HBV infection.