HIV (human immunodeficiency virus) is a virus that damages the cells of your body, leaving it susceptible to various infections you might otherwise be able to recover from. The virus is transmitted easily from one person to the next, and no cure exists. One way to prevent transmission is to undergo testing, which helps determine if you are infected. Knowing this helps you take the proper precautions during sexual intercourse, one of the most common modes of transmission.
The EIA Test
The Centers for Disease Control and Prevention (CDC) states that the enzyme immunoassay (EIA) test is one of the most common tests used for screening. It involves drawing blood from a vein to look for the antibodies produced by the virus. If positive, another test is necessary to confirm the diagnosis.
Various EIA tests are used to identify the HIV antibodies, including the oral fluid test. During this test, a special devices utilized to collect samples of saliva from the mouth. Again, if the results are positive, a follow-up test is required to confirm the diagnosis.
Another form of EIA testing is the urine test. Rather than drawing blood, a urine sample is taken. This test is not as accurate as the blood or oral fluid test. All of these tests are sent to a laboratory to be analysed.
Rapid Testing
Rapid testing is performed much the same way as an EIA; the sample can be blood taken from a vein or oral fluid removed from the mouth. The difference between the two, according to Avert, an international AIDS charity, is that the results come back in 20 minutes because they are not sent to a lab. Just as with the EIA, any positive results must be followed up with another test to confirm the diagnosis.
The Antigen Test
Antigens, as explained by Avert, are the substances responsible for producing the antibodies that cause the HIV virus. The most common antigen is a protein referred to as P24, and this is what the antigen test is looking for.
Due to a low sensitivity, P24 tests are typically not used to diagnose HIV. Instead, it is more effective at immediately after a person has become infected, in the period just prior to the production of the HIV antibodies.
Home Testing Kits
The CDC states that home testing kits were first licensed in 1997. The only model approved by the FDA is Home Access HIV-1 Test System, found at most local drug stores. A person using this kit simply pricks his finger, collects a blood sample, places it on a specially-treated card, and mails the card to a designated laboratory.
Before using the kit, customers are given the option of speaking to a counselor. Once the process is complete, they are given an individual identification number. Used when calling in for the results, this number guarantees accuracy and privacy. If positive, customers are then referred to a hospital or clinic for confirmation testing.
The CD4 Test
The CD4 test is a type of test used to confirm a diagnosis. This is done by measuring the number of T-helper cells, the immune system cell attacked by the HIV virus. Should the HIV virus actually be present, there will be a great reduction in T-helper cells.
