The HIV Antibody blood test screens the presence of antibodies for HIV or Human Immunodeficiency Virus which is the pathogenic agent for non-curable AIDS disease. The HIV antibody blood test can be done on a sample of blood, urine or saliva of the patient.
Any person having unprotected intercourse or multiple partners in last few months must undergo a HIV Antibody blood test as it ensures their current physical status. If you have been exposed to potential HIV infection then you must refrain from further physical relationship until sure that you are not infected. This precautionary measure not only saves others who might be at risk but even stops potential breakout.
The time lag between HIV infection and appearance of HIV antibodies is known as “window period” during which the HIV antibody blood test will give “false negative” results. However, it does not mean the person is not HIV infected.
Exceptions to HIV Antibody Blood Test Results
Though a positive result in HIV antibody blood test means presence HIV infection but there are only two medically accepted exceptions to the result.
Since new born babies don’t have a developed immune system so their body deploys the antibodies received from the mother’s body for fighting disease during initial few months. It means a baby born to a HIV infected mother might test positive for HIV antibody test up to 18 months even when the child might be actually HIV negative.
People taking part in clinical trials of the HIV vaccines might test positive when undergone HIV test, as the HIV antibodies are injected into them though they are not HIV infected.
Accuracy in Comparison to ELISA
The HIV antibody blood tests are very economical and highly accurate. The ELISA ( enzyme linked immunosorbent assay ) was the first widely used HIV diagnosis test however; it is highly sensitive detecting even smallest quantity of antibody so the specificity of the test is lowered by the presence of large quantities of other antibodies.
Any positive result from HIV antibody blood test is followed up by further confirmatory diagnosis. These confirmatory tests include :-
Western Blot Test : It is the most trusted confirmatory HIV diagnosis generally done when two positive results are obtained from either ELISA or HIV antibody blood test.
Second ELISA Antibody Test : Done to confirm the positive result of the first ELISA, as false positives can occur.
A person have had a potential HIV exposure should undergo HIV blood test at 3 weeks, 6 weeks, 3 months and 6 months interval to confirm that they are not HIV infected.