Rapid HIV Screening
HIV test screening is done by checking for the presence of HIV 1/2 antibodies and p24 antigen. Antigen is present in the blood sooner than the antibodies. Antibodies may not be detected till 6 months from the time of exposure.
Published Date : 2023-01-05T09:07:01.559Z
Updated Date : 2023-01-05T09:07:01.607Z
What is p24 antigen
The p24 antigen is a part of the HIV viral protein itself. In effect, it is a direct detection of the presence of HIV in your body. For the rapid screening test to detect the p24 antigen, the virus is required to be present in high enough quantity to permit detection. This is usually seen 3-6 weeks after initial infection.
What are HIV 1 & 2 antibodies
HIV 1 & 2 antibodies are proteins created by your body to fight against the HIV infection. They are present in detectable titres only around 6 months after initial exposure. A negative antibody result does not necessarily mean that you do not have HIV.
How is the test performed?
In order to perform this test, a blood sample is drawn from your vein. After the sample has been collected, it is allowed to clot for 30 minutes. Following the formation of the clot, a rapid flow test is performed using a test kit. The result is read 15 minutes after that.
How long do the results take?
Results are typically available within 30-45 minutes after the blood sample has reached the lab.
What to do if the result is negative?
A negative result may be seen in the extremely early stage post-exposure. This period includes the first 12 - 21 days post infection. During this period only Nucleic Acid Testing (NAT) can detect HIV. NAT Is expensive and only recommended if there is very strong clinical suspicion that you have contracted HIV. NAT Is not routinely recommended for simple screening. It is not a part of the National Guidelines for first line screening. NAT Is advised in special cases
What to do if the test is positive?
A single positive HIV test is not confirmatory. Before doing anything else, the lab will recommend that another sample should be taken, after 1-2 days, and the test is repeated, but using a different method at a different center. If the second test by the alternative method is also positive, it is then necessary to go for final confirmation using the Western Blot Assay. Only after both these two additional tests have been done, can it be said that you are HIV positive. Hence the test discussed in this article is only a SCREENING test.
