Blood tests are important to diagnose past or current infection with hepatitis virus and check the immunity status against future infection. Therefore, it is preferable to have blood tests for hepatitis A and hepatitis B status before vaccination. Vaccination is not required for people who already have protective antibody for hepatitis A virus (HAV) or hepatitis B virus (HBV).
People infected with HBV or hepatitis C virus (HCV) will have a chance to develop chronic hepatitis, which usually goes unnoticed unless being tested. Early diagnosis of hepatitis infection is critical for effective treatment and care.
| Marker | Clinical Interpretation for a Positive Result |
|---|---|
| Anti-HAV | Past or present infection with hepatitis A virus (HAV) or vaccination against HAV; Immune to HAV infection |
| HBsAg | Presence of hepatitis B virus (HBV) infection |
| Anti-HBs | Immune to HBV infection following recovery from infection or vaccination |
| Anti-HCV | Active or past hepatitis C virus infection |
| HCV RNA | Active hepatitis C virus infection |