Testing for HIV

Who should get tested for HIV? How often?

Many people who have HIV may not know it. The only way to find out is by testing for HIV. Testing for HIV is important because

  • there are treatments for HIV that can keep an HIV-positive person healthy and prevent transmission of HIV to others; without an HIV diagnosis a person won’t have access to those medications.
  • when someone does not know they have HIV, they may be more likely to transmit HIV to others by not taking precautions to protect others.

The Centers for Disease Control and Prevention has guidelines about who should be tested and how frequently.

  • All people ages 13-64 should be screened for HIV at least once.
  • All pregnant women should be screened for HIV during the first trimester and third trimester of their pregnancy.
  • People who may be at some risk for HIV should get tested more regularly.
    • Annual testing is recommended for people who
      • are sexually active and who have had a new partner since their last negative HIV test
      • only have one sexual partner, but whose partner has had other sexual partners or has other risk factors such as injection drug use or diagnosis of an STD since their last negative HIV test.
    • Annual or more frequent testing is recommended for anyone who
      • is a man who has sex with men (every 3-6 month testing may be recommended if any condomless anal intercourse, STD in the past year, or other risk factors are present)
      • has had sex with an HIV-positive partner (every 3-6 month testing may be recommended if in an ongoing relationship)
      • injects drugs
      • has been diagnosed with an STD since their last negative HIV test
      • has been diagnosed with Hepatitis or Tuberculosis (TB) since their last negative HIV test
      • has exchanged money or drugs for sex

There are several types of HIV test. This website can help you learn more about different types of HIV test. Here are the basic types of test:

HIV Antibody Tests – Antibody tests do not detect the HIV-virus itself, but detect a protein called an antibody, which is produced by your body in response to the virus. Antibodies are produced by the immune system after it has had time to react to the new infection, which means antibodies are not detectable in the blood or saliva immediately. The “window period” (i.e. the length of time between an HIV-infection and when the test can reliably detect the infection) for antibody-only tests is about 1 month on average, but can take up to 3 months in some people.

Rapid HIV Tests – There are several types of “rapid test” for HIV, all of which are antibody-only tests. Rapid tests are point-of-care tests (done in the moment rather than sent to a laboratory). These tests use either saliva or a small amount of blood (a few drops) and provide a result within 30 minutes. Madison Clinic uses a rapid test that takes a few drops of blood and provides a result in less than 60 seconds. The advantage of using a rapid test is that you don’t have to wait to get the results; however, because a rapid test has a longer “window period” than other tests and because it is a point-of-care test which is more subject to error in its use than a laboratory test, it is recommended that people getting a rapid HIV test also get a standard laboratory test to confirm the results.

Home HIV Tests – The Ora-Quick home HIV test is an antibody-only test that is FDA approved to be done by an individual outside of a healthcare setting. It tests the saliva for antibodies and has a longer “window period” than other tests. These tests are available at many local drug stores, and generally cost about $50 per test.

HIV Antigen/Antibody Tests – The antigen/antibody test is a newer version of HIV test that can detect HIV infection sooner than an antibody-only test. In addition to looking for antibodies, this test is also designed to detect HIV virus antigen, which is a small component of the virus itself. The virus antigen may be present in blood sooner than antibodies, so the “window period” is shorter than an antibody-only test, about two to three weeks after infection.

HIV Confirmation Tests – All of the HIV tests discussed above are highly accurate; however, there is a very small chance of having a false positive result using any of the tests above. If an HIV antigen/antibody or HIV antibody test is positive, the laboratory will always run a second type of test to be sure that the positive result is accurate. At Harborview, this type of test is called an immunoblot test. If both the initial HIV blood test and the confirmatory test are positive, then you and your provider can feel confident that the diagnosis is accurate.

HIV RNA Tests – An HIV RNA Test, also known as an HIV Viral Load Test, detects the HIV-virus itself. This test has a very short “window period,” and can detect the virus about 10 days after infection. This test is rarely used as a screening test because it is much more expensive than the other tests available and provides only a minor improvement on the “window period” over an antigen/antibody test; however, it may be done in follow-up to a positive HIV test or used for screening in specific circumstances, such as if a person had a recent exposure to HIV and is experiencing symptoms of an acute/early HIV infection.