December is AIDS Awareness Month – a perfect time to raise awareness and support for people living with HIV and to educate people on the options and importance of testing for HIV. HIV (human immunodeficiency virus) is a virus that can lead to AIDS (acquired immunodeficiency syndrome).
What types of tests are available, and how do they work?
There are three types of HIV tests: antibody tests, antigen/antibody tests and nucleic acid tests (NAT). Antibodies are produced by your immune system when you’re exposed to viruses like HIV. Antigens are foreign substances that cause your immune system to activate. If you have HIV, an antigen called p24 is produced even before antibodies develop.
An antibody test looks for antibodies to HIV in your blood or oral fluid.
- Most rapid tests and the only HIV self-test approved by the U.S. Food and Drug Administration (FDA) are antibody tests.
- In general, antibody tests that use blood from a vein can detect HIV sooner than tests done with blood from a finger stick or with oral fluid.
An antigen/antibody test looks for both HIV antibodies and antigens.
- Antigen/antibody tests are recommended for testing done in labs and are common in the U.S. This lab test involves drawing blood from a vein.
- There is also a rapid antigen/antibody test available that is done with blood from a finger stick.
A NAT looks for the actual virus in the blood.
- With a NAT, the healthcare provider will draw blood from your vein and send the sample to a lab for testing.
- This test can tell if a person has HIV or how much virus is present in the blood (HIV viral load test).
- A NAT can detect HIV sooner than other types of tests.
- This test should be considered for people who have had a recent exposure or a possible exposure and have early symptoms of HIV and who have tested negative with an antibody or antigen/antibody test.
Talk to your healthcare provider about what type of HIV test is right for you.
How long will it take to get my HIV test results?
- HIV self-tests provide results within 20 minutes.
- With a rapid antibody test, usually done with blood from a finger stick or with oral fluid, results are ready in 30 minutes or less.
- The rapid antigen/antibody test, done with blood from a finger stick, takes 30 minutes or less.
It may take several days to receive your test results with a NAT or antigen/antibody lab test.
Can an HIV test detect the virus immediately after exposure?
No HIV test can detect HIV immediately after infection. That’s because of the window period—the time between HIV exposure and when a test can detect HIV in your body. The window period depends on the type of HIV test. A NAT can usually detect HIV the soonest (about 10 to 33 days after exposure). Learn more about the window period for each HIV test.
If you think you’ve been exposed to HIV in the last 72 hours, talk to a healthcare provider, an emergency room doctor or an urgent care provider about post-exposure prophylaxis (PEP) right away.
Helpful Links
To learn more about HIV and AIDS, visit these links from us and our partners:
- Check out our informative article about HIV and AIDS to read more about the virus, how it’s spread, who’s most at risk and how to tell if you have it.
- Learn more about the causes, symptoms and treatments for AIDS – as well as “do’s and don’ts” for managing the disease – in this link from Carle Health.
- Read more about HIV and AIDS, including information on how HIV progresses, on this webpage from Sarah Bush Lincoln Health System.