Exams and Tests
A thorough medical history and
physical exam 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.
Lower than normal levels may indicate hepatitis or other liver
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
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 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
immunoglobulin (IG) or a dose of the hepatitis A vaccine 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 immunoglobulin
(IG).4 Or they may get the first dose of the hepatitis A vaccine.