Which antibody is indicative of a current or recent Hepatitis A infection?

The presence of IgM antibodies specific to Hepatitis A virus is indicative of a current or recent infection. IgM antibodies are typically the first type of antibody produced in response to an infection, reflecting an active immune response. When a person is exposed to the Hepatitis A virus, their immune system generates IgM antibodies to help combat the infection.

In contrast, IgG antibodies develop later and can indicate past exposure or immunity to the virus but do not confirm an ongoing infection. The Hepatitis A core antibody is not specific to IgM or IgG and is not typically tested in clinical practice for diagnosing acute infection. Lastly, the Hepatitis A surface antigen is a marker for active viral replication but does not specify whether the infection is recent or ongoing versus resolved. Therefore, the presence of IgM antibodies is the most reliable indicator of a current or recent Hepatitis A infection.