Serological Diagnosis of Hepatitis A virus Infection

Hepatitis A cannot be distinguished from other types of viral hepatitis on the basis of clinical or epidemiologic features alone.

Serology is the primary method for the laboratory diagnosis of Hepatitis A Virus infection. IgM anti-HAV is the Reliable marker of acute infection with Hepatitis A Virus. Virtually all patients with acute hepatitis A have detectable IgM anti-HAV.

Timeline for Hepatitis A Virus Infection

 Laboratory testing for IgM anti-HAV is typically positive at the time of onset of symptoms (detectable 5/6 days prior to onset of system) . It remains positive for 3-6 months after primary infection.

The antibody test for total anti-HAV measures both IgG anti-HAV and IgM anti-HAV. Persons who are total anti-HAV positive and IgM anti-HAV negative i.e. presence of IgG anti-HAV in the absence of IgM anti-HAV indicates past infection or vaccination rather than acute infection.