Screening Tests for HIV Diagnosis and Treatment
HIV Tests: Getting a Diagnosis continued...
Rapid antibody/antigen test. One antibody/antigen tests delivers results in 20 minutes.
In-home test kits. These kits -- there are two available in the U.S. -- screen blood and saliva for HIV antibodies. You can buy them at your local store. The Home Access HIV-1 Test System requires a small blood sample that is collected at home and sent to a lab. The user, who may remain anonymous, can get results by phone in three business days. The OraQuick In-Home HIV Test can detect HIV antibodies in saliva, if the antibodies are present (which can take up to 6 months). The user swabs the upper and lower gums of their mouths, places the sample in a developer vial, and can get results in 20-40 minutes. A follow-up test should be done if the result is positive.
To learn where HIV testing is available in your area, call: 800-CDC-INFO (232-4636). If you have a positive HIV test result, see a health care provider who has experience treating HIV and AIDS as soon as possible.
HIV Screening Tests After Diagnosis
While being treated for HIV, your doctor will perform several tests to monitor your health, determine when you need to start treatment, and check how well treatment is working. These include:
CD4 count. CD4 is a protein that lives on the surface of infection-fighting white blood cells called T-helper cells. HIV targets these immune cells.
To monitor the health of your immune system, your doctor will check your CD4 count -- the number of CD4 cells in a sample of blood. You should have your CD4 count tested every three to six months during treatment.
A normal CD4 count is more than 500 cells per cubic millimeter (mm3) of blood. The lower the CD4 count, the less your immune system is functioning, and the more likely you are to get infections. Your doctor will probably start treatment by the time a CD4 count is under 500 cells/mm3. If your CD4 count drops to below 200/mm3, you are said to have full-blown AIDS.
Viral load test. A viral load test measures how much of the HIV virus is in the blood. You want to have a low viral load because it means treatment is helping to control the virus. If your treatment is working effectively, the viral load should drop to an undetectable level in your blood.
You'll have your viral load tested two to four weeks after starting treatment, then every four to eight weeks until the viral load is no longer detectable. An undetectable viral load doesn't mean you're not infected -- just that the amount of HIV in the blood is too low for the test to pick up.