Getting tested is the only way to find out if you have HIV. Early testing is important. If you have HIV, starting treatment early with today’s antiviral drugs may help you live decades longer and lower the risk of passing HIV to your partners.
Should I get tested for HIV?
According to the U.S. Preventive Services Task Force, get tested for HIV if you are:
- Older than 15. All women and girls older than 15 need to be tested at least once.
- Pregnant. Every pregnant woman should have an HIV test as early as possible in the pregnancy. You need to get tested even if you have been tested before. Also, consider getting tested for HIV if you plan to get pregnant.
Some women with HIV don’t know they have it, because HIV may not cause symptoms for several years.
Even if HIV causes no symptoms, it is still causing problems with your body’s immune system that need to be treated as soon as possible.
Some women who test negative assume their partners must be HIV-negative too. But your HIV test reveals only your status, not your partner’s.
When should I get tested for HIV?
If you think you might have been exposed to HIV, get tested. But testing right away may not pick up early HIV infection. The first HIV test taken soon after infection may say that you do not have HIV even if you do. That is because some HIV tests look for antibodies (the body’s natural immune response to a foreign invader) that your body may not have developed yet.
If you get HIV, your body will usually begin to develop antibodies within three to 12 weeks (21 to 84 days). The time between being exposed and developing antibodies is called the “window period.”
There are newer HIV tests available that can tell whether you are HIV-positive early after exposure to the virus. One of the newer tests looks for the virus itself, by testing for viral load (the amount of HIV in your blood) and a marker on the virus called p24 antigen. This test is much more sensitive. It can detect HIV within nine to 11 days after exposure. This type of test may be more expensive. Ask your doctor if this test is available when you get tested for HIV.
How can I get free HIV testing?
Many clinics and doctors’ offices have free or low-cost HIV testing. If you have health insurance, you may be able to get free HIV testing under the Affordable Care Act (the health care law). HIV screening and counseling for women are covered without cost sharing in most private health insurance plans. Medicaid also covers certain recommended preventive services, including HIV screening for women at higher risk for HIV, without cost sharing or deductibles.
HIV testing for people with Medicare is usually covered once every 12 months. Pregnant women with Medicare can get up to three HIV tests for free during pregnancy.
Ask if the newer HIV test, which picks up infection earlier, is available when you get tested for HIV.
The Three HIV Tests explained
There are three types of tests available: nucleic acid tests (NAT), antigen/antibody tests, and antibody tests. HIV tests are typically performed on blood or oral fluid. They may also be performed on urine.
- A NAT looks for the actual virus in the blood and involves drawing blood from a vein. The test can either tell if a person has HIV or tell how much virus is present in the blood (known as an HIV viral load test). 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.
- An antigen/antibody test looks for both HIV antibodies and antigens. 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. Antigen/antibody tests are recommended for testing done in labs and are now common in the United States. This lab test involves drawing blood from a vein. There is also a rapid antigen/antibody test available that is done with a finger prick.
- HIV antibody tests only look for antibodies to HIV in your blood or oral fluid. In general, antibody tests that use blood from a vein can detect HIV sooner after infection than tests done with blood from a finger prick or with oral fluid. Most rapid tests and the only currently approved HIV self-test are antibody tests.
Talk to your health care provider about what type of HIV test is right for you.
How long does it take to get results?
- Laboratory tests (NATand antigen/antibody) require blood to be drawn from your vein into a tube and then that blood is sent to a laboratory for testing. The results may take several days to be available.
- With a rapid antibody screening test, usually done with blood from a finger prick or with oral fluid, results are ready in 30 minutes or less.
- The rapid antigen/antibody test is done with a finger prick and takes 30 minutes or less.
- The oral fluid antibody self-test provides results within 20 minutes.
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 time between when a person may have been exposed to HIV and when a test can tell for sure whether they have the virus is called the window period. The window period varies from person to person and depends on the type of test used to detect HIV. Ask your health care provider or test counselor about the window period for the test you’re taking.
- A nucleic acid test (NAT)can usually tell you if you have HIV infection 10 to 33 days after an exposure.
- An antigen/antibody test performed by a laboratory on blood from a vein can usually detect HIV infection 18 to 45 days after an exposure. Antigen/ antibody tests done with blood from a finger prick can take longer to detect HIV (18 to 90 days after an exposure).
- Antibody tests can take 23 to 90 days to detect HIV infection after an exposure. Most rapid tests and self-tests are antibody tests. In general, antibody tests that use blood from a vein can detect HIV sooner after infection than tests done with blood from a finger prick or with oral fluid.