AIDS diagnosis can be done using body fluids (like blood, saliva), or by using body cells (such as those from the inside of the cheek) of the patient as the sample for HIV testing.

Currently, there are two types of tests that are very commonly used to diagnose an HIV infection in a person. The first test is called ELISA (Enzyme Linked Immunosorbent Assay) test, which looks for the presence of antibodies produced by the host’s body in response to the attack by the Human Immunodeficiency Virus. The second test is called PCR (Polymerase Chain Reaction) test, which looks for the presence of the Human Immunodeficiency Virus itself in the body of the host.

If the ELISA test is positive, it indicates that the antibodies (specific to the Human Immunodeficiency Virus) are present in the host’s body. However, this positive result of the ELISA test needs to be confirmed by conducting others more specific tests such as the Western Blot or Immunoflouroscent Assay (IFA). If the result of this test is also positive, then the person is said to be HIV positive or seropositive.

However, there are some drawbacks to the IFA Test and they are as follows:

1) The HIV specific antibodies are not detectable until 3 to 6 months after contacting the infection

2) The prolonged wait until the results of the test are available.

To overcome this drawback, another test known as the Rapid Test (which has almost the same level of accuracy as the ELISA test) is being used currently. It gives the results in just 5 to 30 minutes, although the test is comparatively much more expensive.

The PCR test is capable of detecting the genetic material of HIV and can, therefore, detect the presence of the virus in a person’s within a few days of contacting the infection.

Other tests for diagnosing HIV include Radio Immuno Precipitation Assay (RIPA), Rapid Latex Agglutination Assay, and p24 Antigen Capture Assay.