Learn about hepatitis a antigen & antibody medical tests in our medical check up knowledge center.

Hepatitis A Antigen & Antibody medical test

Learn about Hepatitis A Antigen & Antibody medical tests, including what the tests are used for, why a doctor may order a test, how a test will feel, and what the results may mean.

What is Hepatitis A Antigen & Antibody test?

Hepatitis A is a highly contagious liver infection caused by the hepatitis A virus (HAV). It is one of several various causes of hepatitis, a condition characterized by inflammation and enlargement of the liver. This test detects antibodies in the blood that are produced by the immune system in response to a hepatitis A infection.

What the Hepatitis A Antigen & Antibody test is used for?

Hepatitis virus testing is done to:

determine the type of hepatitis virus causing the infection.
Screen people who have a higher risk of getting or spreading hepatitis A. This includes medical staff.
Screen blood donors and donor organs. This is done to help prevent the spread of hepatitis A.
Identify if a person has antibodies after getting a hepatitis A vaccination. Having antibodies means the vaccine worked.
Identify if hepatitis A is the reason of abnormal liver function tests.

How is the procedure performed?

A blood sample drawn from a vein in your arm. You may want to wear a shirt with sleeves that can easily be rolled up to make it easier to collect the blood sample.

What will be the results interprets?

Results of hepatitis testing may indicate the following:

HAV IgM	HAV IgG or Total Antibody (IgM and IgG)	Results Indicate
Positive	Not Performed	Acute or recent HAV infection
Negative	Positive	No active infection but previous HAV exposure; has developed immunity to HAV or recently vaccinated for HAV
Not Performed	Positive	Has been exposed to HAV but does not rule out acute infection
Not Performed	Negative	No current or previous HAV infection; vaccine may be recommended if at risk

A total antibody test detects both IgM and IgG antibodies but does not distinguish between them. If the total antibody test or hepatitis A IgG result is positive and someone has never been vaccinated against HAV, then the person has had past exposure to the virus. About 30% of adults over age 40 have antibodies to hepatitis A.

Hepatitis A test
Negative	Hepatitis A virus antibodies absent
Positive	Hepatitis A antibodies are found. You may need more tests to determine if you have a present, active infection or a past infection that got better. IgM antibodies are found if you have an active or a recent infection. These antibodies usually show up as early as 2 weeks after you become infected. They last for a few months after symptoms have gone away. IgG antibodies are found if you had an infection in the past or have been vaccinated.

Hepatitis A test

Negative

Hepatitis A virus antibodies absent

Positive

Hepatitis A antibodies are found. You may need more tests to determine if you have a present, active infection or a past infection that got better.

IgM antibodies are found if you have an active or a recent infection. These antibodies usually show up as early as 2 weeks after you become infected. They last for a few months after symptoms have gone away.
IgG antibodies are found if you had an infection in the past or have been vaccinated.