Tests for HIV can either identify the virus in the blood, or more commonly, detect whether the person’s body has developed antibodies to fight HIV. The most widely used test for antibodies is the ELISA (enzyme-linked immunoabsorbent assay). To check for accuracy, if an ELISA test result is positive, a second test, known as the Western Blot, is used. These tests can determine the presence or absence of HIV antibodies. If there are none, the test results are negative, indicating that the person is probably not infected with HIV. It takes some time for the body to develop antibodies, and so there is a period in which a person is infected with HIV but the test will not reveal it. If the test is positive, antibodies are present in the body, and the person has HIV. It should be noted that false negative and false positive test results are also possible.
Probably the biggest development in diagnosis in the last few years has been the development of rapid HIV testing. Both the ELISA and Western Blot HIV tests require as much as 2 weeks before a result is possible. The OraQuick Rapid HIV Antibody test was the first FDA-approved, noninvasive HIV antibody test. This test detects the presence of antibodies to HIV and requires only a drop of blood. Test results are available within 20 minutes. An oral version of this test, called the OraQuick Advance Antibody Device, has also been approved by the FDA. The oral test collects antibodies from the blood vessels in mucous membranes in the mouth (it does not collect saliva). Unfortunately, both of these rapid tests must be used by trained professionals and because effectiveness rates for these tests are lower than for blood tests, those who test positive are encouraged to follow up with an AIDS blood test.
In late 2005 the Food and Drug Administration began hearing arguments for at – home AIDS testing (Harris, 2005). This debate began in 1987, when the first application for an at-home AIDS test was submitted. The controversy revolves around the lack of counseling and support after using an at-home test. If approved for at-home use, these AIDS tests may come with a 24-hour hotline number.