WHAT IS HIV TESTING?
HIV testing tells people if they have Human Immunodeficiency Virus (HIV). Most of these tests look for antibodies to HIV. Antibodies are proteins produced by the immune system to fight a specific germ. Newer HIV tests can also look for signs of the virus itself in the blood.
People who already know they have HIV might get other laboratory tests. These tests measure how much virus is in the blood (viral load) or the strength of their immune system (CD4 cell count).
HOW DO I GET TESTED?
You can arrange for HIV testing at a public health office, your healthcare provider’s office, or at many community-based organizations that provide HIV testing and prevention services. Test results are usually available within 1-2 weeks. In the U.S., call the National AIDS Hotline (800) 342-2437.
The most common HIV test is a blood test. Newer tests can detect HIV antibodies in mouth fluid (not the same as saliva), a scraping from inside the cheek, or urine. Rapid HIV test results are available within 10-30 minutes after the sample is taken. In November 2010, the FDA approved the INSTI test, which gives results within 60 seconds. In 2012, the FDA approved the first true “in-home” HIV test. It uses a mouth swab and gives results in 20-40 minutes. A positive result on any HIV test should be confirmed with a second test at a healthcare facility.
WHO SHOULD GET TESTED?
Many people have HIV but don’t know it. You might not feel sick or have any health problems, but you can still pass HIV to other people. Anyone who is sexually active should get tested regularly for HIV. The Centers for Disease Control and Prevention (CDC) recommends that everyone between the ages of 13-64 get tested for HIV at least once as part of routine health care. People with certain risk factors should get tested at least once a year or more frequently.
WHEN SHOULD I GET TESTED?
If you are exposed to HIV, it usually takes about 3 weeks to 2 months for your immune system to produce HIV antibodies. During this window period you may test negative for HIV even if you have the virus in your body. If you think you were exposed to HIV, you should wait test right away and then again after 2-3 months.
If you have HIV, you can transmit HIV to others during the window period even if you test negative. In fact, during this early stage of having HIV, you have the greatest chance of transmitting HIV to others.
About 5% of people take longer than 2 months to produce antibodies. Testing at 3 and 6 months after possible exposure will detect almost all HIV infections. However, there are no guarantees as to when an individual will produce enough antibodies to be detected by an HIV test. If you have any unexplained symptoms, talk with your healthcare provider and consider re-testing for HIV.
DO ANY TESTS WORK SOONER AFTER EXPOSURE?
Viral load tests detect pieces of HIV genetic material. These pieces of genetic material show up before the immune system manufactures antibodies.
In 2010, the FDA approved a blood test that detects both antibodies to HIV and HIV antigens (pieces of the virus.) This fourth generation test can detect the presence of HIV sooner than antibody tests alone.
WHAT DOES IT MEAN IF I TEST POSITIVE?
A positive test result means that you have HIV. This can be a very difficult time. Be sure to get information and help. Read more about getting started on HIV treatment.
Testing positive does not mean that you have AIDS. Many people who test positive stay healthy for several years even if they don’t start taking ARVs right away.
If you test negative 3-6 months after you think you were exposed to HIV and if there is no chance you were exposed to HIV since then, you do not have HIV. Continue to protect yourself from HIV. Read more about HIV prevention.
ARE THE TEST RESULTS CONFIDENTIAL?
You can be tested anonymously in many places. You do not have to give your name when you are tested at a public health office or when you receive the test results. You can be tested anonymously for HIV as many times as you want.
If you get a positive result that is not anonymous, or if you get any medical services for HIV treatment, your HIV diagnosis may be reported to the Department of Health and counted in statistical reports.
HOW ACCURATE ARE THE TESTS?
Antibody test results for HIV are accurate more than 99.5% of the time. Before you get the results, the test has usually been done 2 or more times. The first test is called an EIA or ELISA test. Before a positive ELISA test result is reported, it is confirmed by another test called a Western Blot. This is why home test kits cannot tell you if you have HIV. The sample you collect must be tested by a laboratory.
Some special cases can give false or unclear results:
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- Children born to birthing people with HIV may have false positive antibody test results for several months because birthing people pass many types of infection-fighting antibodies to their newborn children. Even if a child does not have HIV, they have HIV antibodies and will test positive for about 18 months. Other tests, such as a viral load test, must be used. Read more about HIV among children.
- People who were recently exposed may test negative during the window period if they get tested too soon after exposure.
- Pregnant people may have false or unclear test results due to changes in their immune system. Read more about HIV and pregnancy.
In unusual cases, HIV test results can be unclear or indeterminate. Another blood sample is taken for additional testing.
THE BOTTOM LINE
HIV testing generally looks for HIV antibodies in the blood, saliva, or urine. The immune system produces these antibodies to fight HIV. It usually takes two to three months for them to show up. In very rare cases, it can take longer than three months. During this window period, you may not test positive for HIV even if have it. Normal HIV tests don’t work for newborn children of HIV-infected mothers.
In many places, you can get tested anonymously for HIV. Home HIV tests are also available. Once you test positive and start to receive healthcare for HIV, your name may be reported to the Department of Health. These records are kept confidential.
A positive test result does not mean that you have AIDS. If you test positive, you should learn more about HIV and decide how to take care of your health.
MORE INFORMATION
CDC: HIV Testing
CDC: Find an HIV test near you
CDC: Find self-testing services in your state
Planned Parenthood: Should I get tested for HIV?
Reviewed June 2024
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