SwabTest offers a test for hepatitis B that detects the hepatitis B surface antigen (HBsAg) and antibodies to the hepatitis B core (anti-HBc). Although each of these assays are highly accurate, additional tests may still be required.
People who are HBsAg negative AND anti-HBc negative are not currently infected with hepatitis B, nor have they had a previous exposure to hepatitis B. However, these two assays do not detect people who have immunity to hepatitis B through vaccination. The anti-HBc test is required to detect immunity due to vaccination (not offered by SwabTest).
People who are HBsAg negative AND anti-HBc positive are likely immune due to a past, resolved infection. However, usually this must be confirmed with a positive result in an anti-HBc test.
People who are HBsAg positive AND anti-HBc positive have a current hepatitis B infection. However, additional testing (IgM anti-HBc and anti-HBs) is required to distinguish between an acute and chronic infection.
HBsAg positive AND anti-HBc negative is a rare combination, but is likely indicative of a very early acute infection.