How do we determine if someone is infected with HBV? Three serologic tests are
usually done to evaluate a person for HBV exposure: HBsAg, anti-HBc, and anti-HBs.
usually done to evaluate a person for HBV exposure: HBsAg, anti-HBc, and anti-HBs.
- First, the HBsAg. The presence of HBsAg indicates infection with HBV.
- Next, the anti-HBc. The anti-HBc is positive before the HBsAg becomes positive. In persons at risk for acute infection (known recent exposure or high liver enzyme level), the HBc immunoglobulin M (IgM) should be ordered as this may be the only serologic evidence of HBV exposure. In people with chronic HBV infection, the anti-HBc is predominantly immunoglobulin G (IgG), and the presence of anti-HBc confirmsan active or prior infection.
- And, last, the anti-HBs. A positive anti-HBs indicates immunity from either exposure or vaccination.
