
There are three types of HIV test:
HIV Antibody Test
The HIV antibody test is the most common test during a sexual health check. If you have contracted HIV, your immune system will start producing antibodies reacting to the virus within 2-12 weeks following exposure. These antibodies are detected by the test, and if you were tested positive, another test will be done to confirm the result.
HIV Antigen Test
An antigen test will detect HIV infection at an earlier stage than an HIV antibody test. It tests for quantities of a protein known as the p24 antigen, which is part of the HIV and produced in high amounts early on after contracting HIV. Our Health Service Centre currently test for both HIV antibodies and the p24 antigen. Our HIV rapid test can detect p24 antigen within 15-28 days after infection. We are also providing counseling and follow-up services to those who are tested positive for HIV.
Nucleic Acid Tests (NAT)
NATs look for the actual virus in the blood and involves drawing blood from a vein. The test can detect how much virus is present in the blood (known as an HIV viral load). While a NAT can detect HIV sooner than other types of tests, this test is very expensive and not routinely used for screening individuals unless they recently had a high-risk exposure or a possible exposure and have early symptoms of HIV infection.
Book a free test:
https://aidsconcern.org.hk/en/testing-service/bookatest/
Purchase your HIV self-test kit:
https://aidsconcern.org.hk/en/testing-service/self_testing/
*The above approaches are only for HIV prevention but not other STIs.

11. How long does it take to get results?
With a rapid antigen/antibody screening test, usually done with blood from a finger prick, results are ready in 30 minutes or less. The oral fluid antibody self-test provides results as quickly as 20 minutes.
Laboratory tests (NAT and antigen/antibody) require blood to be drawn from your vein into a tube and that blood is sent to a laboratory for testing. The results may take several days to be available.
22. How soon after an exposure to HIV can a test detect if I have the virus ?
No HIV test can detect HIV immediately after infection. If you think you’ve been exposed to HIV in the last 72 hours, talk to your health care provider about post-exposure prophylaxis (PEP), right away.
The detection timeframe of HIV depends on the test you are taking:
Nucleic Acid Test (NAT): 10 to 33 days after exposure
Antigen Test: within 15-28 days after exposure
Antibody Test: 90 days after exposure
Remember, you can only be sure you are HIV-negative if: Your most recent test is after the window period. You haven’t had a potential HIV exposure during the window period. If you do have a potential exposure, then you will need to be retested.
Remember, you can only be sure you are HIV-negative if: Your most recent test is after the window period. You haven’t had a potential HIV exposure during the window period. If you do have a potential exposure, then you will need to be retested.
33. If I test positive for HIV, does that mean I have AIDS?
No. Being HIV-positive does not mean you have AIDS. AIDS is the most advanced stage of HIV disease. HIV can lead to AIDS if a person does not get treatment or take care of their health after infection. But if a person with HIV takes their HIV medicine as prescribed, they may stay healthy for many years, and may never be diagnosed with AIDS.
44. Will other people know my test result ?
Your HIV test results are completely anonymous and confidential! Anonymous testing means that nothing ties your test results to you. When you take an anonymous HIV test, you get a unique identifier that allows you to get your test results. You can also purchase a self-test if you want to test privately and anonymously.