Hepatitis A: Exams And Tests

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Exams and Tests

A thorough medical history and physical examination provide valuable information about your symptoms and whether it is likely that you have been exposed to the hepatitis A virus (HAV).

While taking a medical history, your doctor usually will ask where you have traveled, if you work in or have a child in a day care center, and if you live with someone known to have hepatitis A.

If you may have been exposed to hepatitis A, you will have blood tests to study liver function and to see whether your liver is damaged or inflamed. Blood tests to study liver function include:

• Bilirubin. When bilirubin builds up in the blood, it may indicate hepatitis.
• Albumin. Lower than normal levels may indicate hepatitis or other liver problems.
• Prothrombin time, a blood test that measures how long it takes blood to clot. An abnormal prothrombin time can be caused by liver disease or injury.

Blood tests that may be done to determine whether the liver is damaged or inflamed include:

• Alanine aminotransferase (ALT). When the liver is damaged or diseased, ALT is released into the bloodstream, causing levels of the enzyme to rise.
• Aspartate aminotransferase (AST). When body tissues or organs such as the heart or liver are damaged, AST is released into the bloodstream. The amount of AST in the blood is directly related to the extent of the tissue damage.
• Alkaline phosphatase (ALP). Large amounts of ALP in the bloodstream may indicate liver damage.
• Lactic dehydrogenase (LDH). Many diseases can cause elevations in LDH levels. In addition to the LDH test, your doctor will usually run other tests to confirm a diagnosis of hepatitis A.

If tests show your liver is inflamed, you will have an antibody (anti-HAV) test on a sample of your blood. The presence of HAV antibodies means that HAV infection is the most likely cause of your hepatitis.

If the results of the anti-HAV test show that HAV is not multiplying in your body, your doctor may do other hepatitis blood tests to find out whether hepatitis B virus, hepatitis C virus, or Epstein-Barr virus (which causes infectious mononucleosis, or “mono”) is causing your hepatitis.

Early Detection

If you are concerned that you have been exposed to the virus and you have not been previously infected or vaccinated, contact your doctor. If you get a shot of immune globulin (IG) within 2 weeks of being exposed to HAV, you probably will not develop symptoms of HAV infection.

Routine vaccination of hospital workers, food handlers, and child care center workers and attendees does not occur at this time because their chance of infection generally is no greater than that of the wider community. But some child care centers have workers get the shot because it works so well to prevent the disease. Plus there is very low chance of side effects from the vaccine. If outbreaks of HAV infection do occur in those settings, people who were exposed to the virus should receive a shot of immune globulin (IG).⁴

Last updated:	September 09, 2008
Author:	Maria G. Essig, MS, ELS
Reviewed By:	Kathleen Romito, MD - Family Medicine, W. Thomas London, MD - Hepatology
Editors:	Susan Van Houten, RN, BSN, MBA, Pat Truman, MATC