HIV Testing

An HIV test is used to detect if a person is positive for the human immunodeficiency virus.

There are various HIV tests that can be done by a person who suspects of having HIV. These tests vary mostly in what they test for and their window periods. The term ‘window period’ means the period of time between the initial HIV infection and the indicators of HIV showing up on tests.

hiv testingThe different HIV tests are listed below:

  • HIV Antibody tests: HIV antibody test also called RNA test looks for antibodies that fight the HIV infection. This test is inexpensive and very accurate but is most effectively used three months after an initial infection. Once an antibody test resultspositive, this means that HIV is present in the body. There are also cases when the result shows false-positive results:
    • A newborn baby who has an HIV positive mother keeps the mother’s antibodies for up to 18 months. If an antibody test is done to the baby, he or she may have a false-positive result.
    • There are some people who have received HIV vaccines trials for research purposes. Their bodies might develop antibodies that fight HIV so once an antibody test is done, they might get a positive result although they do not have HIV.
  • Antigen test (p24 test): Antigens are foreign substances that cause the body’s immune system to make antibodies. An antigen test looks for the p24 viral proteins in the body. This p24 can be detected in early stage of HIV infection because once HIV has been fully established in the body, the p24 antigen levels fades, thus an antigen test is rarely used nowadays because it has a very low sensitivity.
  • Fourth generation tests: This test combines p24 antigen test with standard antibody test. This modern HIV test simultaneously detects p24 and antibodies and gets a more accurate result. This window period of fourth-generation tests is 11 days to a month after an initial HIV infection.
  • Polymerase Chain Reaction test (PCR): Also called Nucleic acid-based test (NAT), this test detects the genetic material of HIV. This test can be done two to three weeks after an initial infection.

HIV testing is recommended for anyone who has never been tested before, or if you have had unprotected sex since your last test with someone whom you are unsure of their HIV status. If you have had a recent encounter, consider our 10 panel test or the standalone HIV early detection test.