what lab shows active hepatitis a
Guide. Hepatitis A virus (HAV) test is a blood test that looks for proteins (antibodies) made by the body in response to the virus that causes hepatitis A. These proteins will be present in your blood if you have a hepatitis A infection now or have had one in the past. IgM anti-HAV antibodies mean a recent infection with hepatitis A virus. 2  IgM anti-HAV antibodies generally can be detected in the blood as early as 2 weeks after the initial HAV infection.