HIV BASICS - TESTING

The only way to know if you have HIV is to get tested. Knowing your HIV status gives you powerful information to keep you and your partner(s) healthy. This section answers some of the most common questions about HIV testing, including the types of tests available, where to get one, and what to expect when you get tested.

CDC recommends everyone between the ages of 13 and 64 get tested for HIV at least once.

People at higher risk should get tested more often. If you were HIV-negative the last time you were tested, the test was more than one year ago, and you can answer yes to any of the following questions, then you should get an HIV test as soon as possible:

• Are you a man who has had sex with another man?
• Have you had sex—anal or vaginal—with a partner who has HIV?
• Have you had more than one sex partner since your last HIV test?
• Have you injected drugs and shared needles, syringes, or other drug injection equipment (for example, cookers) with others?
• Have you exchanged sex for drugs or money?
• Have you been diagnosed with or treated for another sexually transmitted disease?
• Have you been diagnosed with or treated for hepatitis or tuberculosis (TB)?
• Have you had sex with someone who could answer yes to any of the above questions or someone whose sexual history you don’t know?

You should be tested at least once a year if you keep doing any of these things. Sexually active gay and bisexual men may benefit from more frequent testing (for example, every 3 to 6 months).

If you’re pregnant, talk to your health care provider about getting tested for HIV and other ways to protect you and your child from getting HIV.

Before having sex for the first time with a new partner, you and your partner should talk about your sexual and drug-use history, disclose your HIV status, and consider getting tested for HIV and learning the results.

Knowing your HIV status gives you powerful information to keep you and your partner healthy.

• If you test positive, you can take medicine to treat HIV. Taking HIV medicine as prescribed can make the amount of HIV in your blood (viral load) very low—so low that a test can’t detect it (called an undetectable viral load). Getting and keeping an undetectable viral load is the best thing you can do to stay healthy. If your viral load stays undetectable, you have effectively no risk of transmitting HIV to an HIV-negative partner through sex.
• If you test negative, there are more HIV prevention tools available today than ever before.
• If you are pregnant, you should be tested for HIV so that you can begin treatment if your test is positive. If a woman with HIV is treated early in her pregnancy, the risk of transmitting HIV to her baby is extremely low (1% or less).

CDC recommends that everyone between the ages of 13 and 64 get tested for HIV at least once as part of routine health care, and more often if you do things that might increase your risk for getting HIV.

Even if you are in a monogamous relationship (both you and your partner are having sex only with each other), you should find out for sure whether you or your partner has HIV.

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.

• Laboratory tests (NAT and 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 a quickly as 20 minutes.

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.

If you get an HIV test after a potential HIV exposure and the result is negative, get tested again after the window period. Remember, you can only be sure you are HIV-negative if:

1. Your most recent test is after the window period.
2. 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.

You can ask your health care provider for an HIV test. Many medical clinics, substance abuse programs, community health centers, and hospitals offer them too. You can also find a testing site near you

If you get a test in a health care setting or lab, a health care provider or lab technician will take your sample (blood or oral fluid). If it’s a rapid test, you may be able to wait for the results, but if it is a laboratory test, it can take several days for your results to be available. Your health care provider or counselor may talk with you about your risk factors, answer any questions you might have, and discuss next steps with you, especially if your result is positive.

• If the test comes back negative, and you haven’t had a possible exposure during the window period for the test you took, you can be confident you don’t have HIV.
• If your test result is positive, the lab will conduct follow-up testing, usually on the same blood sample as the first test.

If you are tested outside of a health care setting or a lab, you will likely receive a rapid test (oral fluid or finger stick).

• If the test comes back negative, and you haven’t had a possible exposure during the previous 3 months, you can be confident you don’t have HIV.
• If your test result is positive, you should go to a health care provider to get follow-up testing. Counselors providing the test should be able to answer questions and provide referrals for follow-up testing as well.

There is currently only one FDA-approved self-test (Oraquick). HIV self-tests can be bought in stores, and online. Some health departments and other organizations may have programs that allow you to get a self-test for you and your friends at reduced cost or for free. A self-test may be used in your home, or in a private area in a testing clinic. For a self-test, you have to swab your own mouth to collect an oral fluid sample and use a kit to test it. You will be able to get a result in about 20 minutes. It is important to follow the directions as described in the instructions or the test will not work properly. There is a phone number included with a HIV self-test for anyone to call to get help with conducting the test.

You should always interpret a self-test according to the test manufacturer’s instructionsexternal icon.

• If the test comes back negative, and you haven’t had a possible exposure during the previous 3 months, you can be confident you don’t have HIV.
• If your test result is positive, you should go to a health care provider to get follow-up testing.

Note: Some people have difficulty in conducting an HIV self-test and the test does not perform as it should. If an HIV self-test is invalid as described in the instructions, then the test has not worked. In this case, you will need to use another HIV self-test, or seek testing at a health care provider or testing center.

All pregnant women should be tested for HIV so that they can begin treatment if they’re HIV-positive. If a woman is treated for HIV early in her pregnancy, the risk of transmitting HIV to her baby is extremely low (1% or less). Testing pregnant women for HIV infection and treating those women who have HIV has led to a huge decline in the number of children born with HIV.

The treatment is most effective when started as early as possible during a pregnancy. However, there are still great health benefits to beginning preventive treatment even during labor or shortly after the baby is born.