HIV 1 and 2 Antibody, Rapid Screening Test

HIV is transmitted through sexual contact, by sharing needles or syringes for intravenous use, by blood transfusion from an HIV-infected person, or by an infected mother to an unborn baby. For the first few weeks of an HIV infection, the patient may have a flu-like illness and the HIV increases rapidly in blood. After 2-8 weeks, the body starts producing antibodies against the virus and these can then be detected in the blood. The typical course of HIV infection includes three stages: primary or acute infection, chronic or clinical latency stage, and finally AIDS when HIV has severely damaged the immune system.

An HIV 1 and 2 Antibody, Rapid Screening Test detects the presence of HIV antibodies in blood. These antibodies may take about 6-12 weeks (upto 6 months in some cases) to form after infection/ exposure, in detectable quantity. This period is called the window period. During this period the HIV antibodies are not detected in the test but the person can infect others.

Your doctor may advise this test if you show symptoms of HIV infection, such as sudden weight loss, night sweats, extreme tiredness, swollen lymph nodes, white spots in your mouth, pneumonia, forgetfulness, depression, etc. You may also get tested if you are at risk of acquiring HIV infection or have been exposed to the blood of an HIV-infected individual. This test also helps to differentiate between HIV-1 and HIV-2 infection. However, since there is high cross-reactivity between the two subtypes, it needs to be confirmed by Western Blot and/or HIV RNA PCR (as viral load monitoring test).

If an infection is confirmed, the test results are said to be positive, while if there is no virus detected, the test results are said to be negative. Sometimes the test may be negative even though you may be harboring the virus. This happens due to the window period. The window period represents the period between infection with HIV and the time when HIV antibodies can be detected in the blood. A blood test performed during the window period may yield a negative test result for HIV antibodies. These cases may require further testing after 12 weeks. The antibody test is not advised in children below 18 months of age, due to the persistence of the mother's antibodies. Then the diagnosis of HIV is made by Polymerase Chain Reaction (PCR) tests that detect HIV nucleic acid.

You may talk to your doctor about all the pre-test instructions. No special preparation is required for this test; eat or drink normally as per your daily routine. However, a duly filled consent form is mandatory for sample collection. As per NACO guidelines, all reactive samples are tested by three different methods before the release of the report. All reactive results must be confirmed with a Western Blot Test. 

Test result ranges are approximate and may differ slightly between different labs depending on the methodology and laboratory guidelines. Talk to your doctor about your specific test results. Narrate your complete medical history to help the doctor correlate your clinical and laboratory findings. The test results will help them determine your medical condition, make recommendations for lifestyle modifications such as diet and exercise, decide whether or not medication will be required to manage your condition and formulate your overall treatment plan.