What is the HIV Test?
The standard HIV antibody test (called an ELISA) is a blood test that doesn't actually detect HIV, but detects your immune system's response to the virus. When your body is infected by a virus (or anything else), special white blood cells make proteins called antibodies to help neutralize and attack the infecting agent. Even though antibodies cannot protect you from HIV, they are useful in making the virus's presence known.
HIV-antibody test results usually come back in about a week. If the test is positive, which means antibodies were detected, then a more accurate test called a Western Blot is performed. This test looks for actual evidence of HIV, not just antibodies. Combined, the HIV antibody test and the Western Blot test can detect HIV in more than 99.5 percent of those infected. If both these tests are positive, most patients then undergo a polymerase chain reaction (PCR) assay, which determines the actual level of HIV in the blood. Although the PCR test gives the quickest result, it is so sensitive that it often gives a false positive result. Considering its sensitivity and high cost, the PCR test is not considered an effective routine screening test for HIV.
Are There Flaws in the HIV Test?
Yes. Since your body may take anywhere from weeks to months to make antibodies after HIV infection, there is a "window" of time when the antibody test will give a false negative result. This means you may actually have HIV, but the test says you don't. To be on the safe side, we say that the HIV test has a six-month window to be false negative. So, to ensure that you are HIV-negative now, you'll need to repeat the test in six months to a year from now. A negative test result basically means only that you were HIV-negative six months ago. If during that time you continue to be at risk for contracting the virus, you'll have to get tested yet again. Unless you are abstinent or in a monogamous relationship (and you should always be skeptical) you should probably get tested for HIV at least once every few years.
Current evidence indicates that if HIV infection is more advanced before treatment is begun, therapy is less likely to be successful than it would be had the HIV infection been caught earlier on. Therefore, one of the keys to successful treatment is starting early. Don't wait. Get tested now.
For a testing or treatment center, contact:
National AIDS Hotline
(800) 342-AIDS (2437)
HIV/AIDS Treatment Information Service
(800) 448-0440
