How Is the AIDS Test Performed?

Blood Tested for Antibodies

According to the Centers for Disease Control, "Once HIV enters the body, the body starts to produce antibodies---substances the immune system creates after infection." These antibodies function to help protect your body against the HIV virus. The San Francisco AIDS Foundation states that the "window period" is the "time it takes for a person who has been infected with HIV to react to the virus by creating HIV antibodies. This is called seroconversion." In most cases these antibodies can be detected within three to six months after infection.

RNA Test

Another blood test can be performed to detect the actual virus. This test is called an RNA test. For this test the HIV virus can be detected as early as nine to 11 days after infection. However, this is a more costly test, so it is not used as frequently.

Blood Sample

According to the National HIV Test Site, blood samples are the most common way to test for AIDS. There are rapid tests and also home test kits called EIA (enzyme immunoassay). Blood can be drawn from a finger prick or vein. For home tests the National HIV Test Site states that "the testing procedure involves pricking a finger with a special device, placing drops of blood on a specially treated card, and then mailing the card in to be tested at a licensed laboratory." The rapid tests can provide results in approximately 20 minutes. If your initial test comes out positive, you will need to take a Western blot test to confirm a diagnosis. This test produces results in a few days to a few weeks.

Oral Fluid and Urine Tests

While not as accurate, oral fluid (not saliva) that is collected from the mouth using a special collection device can also be tested. Urine tests can also be used. These tests also detect the HIV antibodies and require a follow-up Western blot test if your test result is positive.

Interpretation of Results

A positive (reactive) test result means that you have the virus that causes AIDS and you can infect others who come into contact with your blood, semen or vaginal fluid. This does not mean that you have or will definitely get AIDS. A negative (non-reactive) result means that you are not carrying the virus at that time. However, caution is urged as the antibodies may not yet be high enough to be detected. If you are at risk for HIV infection, you are encouraged to get tested again.