Entamoeba histolytica Antibody
Does this test have other names?
Amebiasis antibody test
What is this test?
This blood test tells your healthcare provider whether you have antibodies in your
blood to the parasite Entamoeba histolytica. This parasite causes the disease amebiasis.
If you have been infected with E. histolytica, your immune system may make these antibodies.
Your immune system makes proteins called antibodies to attack foreign invaders like
Why do I need this test?
You may need this test if you have symptoms of amebiasis. Amebiasis occurs when the
parasite E. histolytica gets into your digestive system after you eat food or drink
water contaminated with the parasite or put anything in your mouth that has been contaminated.
In most cases this parasite can be found by looking for it in a stool sample under
a microscope. If you have symptoms of amebiasis but the parasite has not been found
in your stool sample, or your healthcare provider thinks the parasite may have spread
outside your digestive system, you may need this test. Amebiasis is more common in
tropical countries that have poor sanitation. If you have lived or traveled in a place
that has poor sanitation, your healthcare provider may suspect amebiasis if you have
What other tests might I have along with this test?
You may have one or more stool samples tested to look for E. histolytica.
What do my test results mean?
Many things may affect the results of a lab test. These include the method the laboratory
uses to do the test. Even if your test results are different from the normal value,
you may not have a problem. To learn what the results mean for you, talk with your
If antibodies to E. histolytica are found, they are measured in units called titers.
This is what your test results may mean:
A titer less than 1:32 means you probably do not have amebiasis.
A titer greater than 1:128 may mean an active or recent amebiasis infection.
A titer between 1:256 and 1:2048 likely means a current and active amebiasis infection.
How is this test done?
The test requires a blood sample, which is drawn through a needle from a vein in your
Does this test pose any risks?
Taking a blood sample with a needle carries risks that include bleeding, infection,
bruising, and a sense of lightheadedness. When the needle is put in your arm, you
may feel a slight stinging sensation or pain. Afterward, the site may be sore.
What might affect my test results?
Once you develop antibodies to E. histolytica, they may stay in your blood even after
you no longer have amebiasis. Because of this, in some cases a positive antibody test
may only mean you have been exposed to the parasite in the past, not that you have
a current infection.
How do I get ready for this test?
You don't need to prepare for this test.