Acute Hepatitis A Antibody Test

What this test measures

IgM is the first antibody class the immune system produces during a new infection. In hepatitis A, anti-HAV IgM usually becomes detectable early in the illness and then declines over the following months. This makes it a useful marker when a clinician is assessing a suspected acute infection rather than long-term immunity.

Only a serum sample from a standard blood draw is needed. The laboratory reports anti-HAV IgM, and some panels include total antibody, IgG, HAV RNA, and liver enzymes such as ALT, AST, and bilirubin for a fuller picture. The combination of markers helps distinguish recent infection from past exposure or vaccination.

People often order this test after a known exposure, during an active outbreak investigation, or when persistent symptoms such as fatigue, nausea, abdominal discomfort, or jaundice require evaluation. Results are always interpreted by a qualified healthcare provider and are not a stand-alone diagnosis.

• Anti-HAV IgM antibodies
• Anti-HAV total antibodies
• Anti-HAV IgG antibodies
• HAV RNA by molecular testing when indicated
• ALT (liver enzyme context)
• AST (liver enzyme context)
• Total bilirubin
• Alkaline phosphatase

Why people order this test

• Evaluate a suspected recent hepatitis A infection
• Investigate symptoms after a known exposure
• Support public health or outbreak-related testing
• Distinguish recent infection from past immunity
• Provide context alongside liver enzyme results

How to prepare

No fasting is needed, and collection can occur at any time of day. A venous blood sample is drawn at a laboratory. Follow the collection instructions provided by the laboratory.

Understanding your results

Results are usually available within one to three business days. A positive IgM result can support the diagnosis of a recent infection, while a negative result does not rule out every stage of illness; a healthcare provider makes the final assessment.