What are the other Names for this Test? (Equivalent Terms)
- HAV-Ab IgM and IgG Blood Test
- HAV-Ab IgM Blood Test
- HAV-Ab Total Blood Test
What is Hepatitis A Blood Test? (Background Information)
- The hepatitis A virus (HAV) infects the liver, causing damage and inflammation (hepatitis). It is transmitted feco-orally (from infected stools to mouth), through consumption of infected food and water
- Hepatitis A Blood Testing looks for the presence of antibodies in the blood of individuals, who have been exposed to the hepatitis A virus
- The first type of antibody to appear following an exposure to HAV, is IgM. This can be detected in blood, 2-3 weeks following and infection and it persists in blood, for 2-6 months
- The IgG type of antibody appears in blood, a few weeks after IgM, and it remains in the body for years
- Testing for HAV virus involves estimating the IgM antibodies and the total antibodies to HAV (both IgM and IgG) in individuals:
- Who have signs and symptoms of hepatitis A
- Who have likely been exposed to the virus (to aid in a diagnosis)
- Also to help in ascertaining the need for vaccine in susceptible individuals
What are the Clinical Indications for performing the Hepatitis A Blood Test?
A physician may order Hepatitis A Blood Tests in individuals presenting with signs and symptoms suggestive of hepatitis, such as:
- Abdominal pain
- Nausea, vomiting
- Dark urine
- Pale stools
Certain other indications for testing include:
- Asymptomatic individuals with likely exposure to the virus
- To determine if the individual is a candidate for vaccination against hepatitis A virus (when no antibodies are detected against HAV in blood, the individual is susceptible to infection)
How is the Specimen Collected for Hepatitis A Blood Test?
Sample required: Blood
Process: Blood sample is obtained through a needle inserted into a vein in the arm.
Preparation required: None
What is the Significance of the Hepatitis A Blood Test Result?
The Hepatitis A Blood Test may have the following outcomes:
- IgM positive and total antibodies negative: Indicates acute hepatitis A viral infection
- IgM negative and total antibodies positive: Indicates a past infection with HAV, or likely post-vaccination
- IgM negative and total antibodies negative: Neither is there an exposure to HAV, nor is the individual vaccinated; hence, there is a susceptibility to infection
The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.
Additional and Relevant Useful Information:
- Antibodies to hepatitis A virus may be present in about 30% of the adults, over 40 years of age
Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider, the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.