HIV Tests

What are HIV tests?

Most HIV tests check for antibodies to the human immunodeficiency virus. HIV is the virus that causes AIDS (acquired immunodeficiency syndrome), a life-threatening disease. If you are infected with HIV, your immune system makes antibodies, which are substances that try to destroy or get rid of the virus. In the case of HIV, these antibodies are usually unable to fight off the infection, but the presence of antibodies is used to see if you have HIV in your body. There are tests that look for the virus itself, but they are not the best tests to diagnose HIV infection.

Why is this test done?

HIV antibody tests are done to see if you are infected with the virus that causes AIDS. This test is also used to screen donated blood for HIV. There is no way to know without testing if you are infected with HIV. Learning whether you are HIV positive will help you care for yourself and protect others from infection.

How do I prepare for this test?

It is important to get counseling before or when you have the HIV test. This can help to identify things you do that may increase your risk for HIV infection.

How is the test done?

There are blood antibody tests and mouth (oral) swab antibody tests. In both cases a positive result indicating HIV infection needs to be confirmed by a blood sample drawn from your arm.

The quick-result blood test requires a small amount of blood to be taken from your finger or arm. The blood from a finger prick is put in a vial of solution and tested with a dipstick. Blood taken from your arm with a needle is sent to a lab for testing. If the first test is positive, this sample can be used to do the test that confirms HIV.

Instead of blood, some hospitals and clinics may take a sample of fluid obtained from your mouth by swabbing your gums or by leaving a swab in your mouth (between your cheek and gums) for a few minutes. The results of this test will be available to you the same day. If this test is positive, then you will need blood drawn from your arm to send for the confirming test.

Having an HIV test takes just a few minutes of your time. There is no risk of getting AIDS, hepatitis, or any other blood-borne disease from this test.

Home test kits have become available through the Internet. However, some of these tests have been shown to be inaccurate. The only home HIV test approved by the Food and Drug Administration (FDA) is the Home Access HIV-1 Test System. It can be bought at most local drug stores. When you do this home test, first you register by phone. Then you collect a sample of blood by pricking a finger with a special device, placing drops of blood on a specially treated card, and then mailing the card in to be tested at a licensed lab. Toll-free telephone support is available 24 hours a day for test and result questions. Like the positive results from the first HIV tests done by a healthcare provider, positive results from a home test need to be confirmed with more testing by your provider.

How will I get the test result?

Ask your healthcare provider when and how you will get the result of your test. Results from the finger-prick or gum-swabbing HIV tests may be available in 30 minutes or less. You may get results from other HIV tests in 2 to 10 days.

The test results are confidential. However, positive results may be reported to the state health department for 2 reasons.

• The first reason is to provide help with notifying others who may have been exposed to HIV (your name will not be used). The health department will call the people with whom you have had intimate contact. They will tell them that they have been named as a contact of someone who has tested positive for HIV and they need to be tested. In the case of an on-going relationship you may bring your partner to your healthcare provider for discussion and testing.
• The second reason is to provide reports to the federal government so there can be a count of how many people have HIV. The count helps determine where and how the virus is spreading and how much money each state needs for HIV prevention and care.

Some centers offer anonymous testing. Anonymous testing does not use your name at all. Positive results are reported without any personal identifiers. Some people feel this better protects the confidentiality and civil rights of people who test positive for HIV.

What do the test results mean?

In general, a positive HIV test means that you are infected with HIV, and a negative test means that you are not infected with HIV. Because it takes at least a few weeks for HIV antibodies to show up in the blood after you have been infected by the virus, it is possible to have a negative test if you have been just recently infected (this is called a false negative test). In this case, the test will become positive if it is repeated several weeks or months later. If you have a negative test result but you are at high risk for infection, you may need to have another test in 3 to 6 months. Most people develop detectable antibodies within 2 to 8 weeks after infection with the virus (the average is 25 days). However, some people take longer to develop detectable antibodies.

Sometimes an HIV test result can be positive even though you do not have HIV infection (this is called a false positive test). For this reason, when a test result is positive, labs do a second HIV test (such as the Western blot) to check the result. The Western blot takes longer to perform and is more expensive than the first test, but it is more precise.

What if my test result is positive?

If your first test for HIV is positive, you should have more blood tests to confirm the results. If repeat tests are positive, you should seek medical care, even if you have no symptoms. You may need to start taking medicine to try to stop the HIV infection from developing into AIDS. You need to discuss the test results with your healthcare provider or an HIV counselor as soon as possible to protect your health and the health of people you love.