HIV Screening Test

Urgent safety information

If you think you were exposed to HIV, talk with your health care provider right away about emergency treatment, called PEP (post-exposure prophylaxis). PEP may prevent an HIV infection if it is started within three days after a possible exposure. The sooner you start, the better.

Why this test may be ordered

• Routine screening: The CDC recommends everyone ages 13–64 get tested at least once as part of routine health care.
• After a possible exposure to find out if you were infected.
• If you have a higher risk for infection (e.g., had sex with someone who has HIV or whose status you don't know, shared needles or drug items, exchanged sex for money or drugs, had an STI like syphilis, or had sex with anyone who has done these things).
• If you are pregnant, because HIV can be passed to the fetus or baby, and medicines can greatly reduce that risk.
• If you have had hepatitis or tuberculosis, you should be tested at least once a year.

Preparation and collection

You don't need any special preparations for an HIV test. If you are getting tested in a health clinic or community program, a counselor may talk with you about your risk for HIV. So, you may want to write down any questions you have ahead of time.

If you go somewhere for your test, a staff person or counselor will explain what type of sample will be taken and how. If you do a test at home, be sure to follow all the instructions that come with your test kit. For blood from a vein, a health care professional will take a blood sample from a vein in your arm, using a small needle. For a saliva sample, a health care professional will wipe a special swab along your gums.

There is very little risk to having any HIV screening test. If you have blood taken from a vein, you may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

Understanding results

Getting tested for HIV helps catch the virus early so you can start treatment, stay healthy, and avoid spreading HIV.

• Negative (no signs of HIV infection found): A negative test result means that no signs of an HIV infection were found in your sample. Limitation: But that doesn't always mean that you don't have HIV. You could have an HIV infection, but it's too soon for the test to tell and you may need another test later. Next step: Your provider or an HIV counselor can explain your test result and let you know if you need another test.
• Positive (signs of HIV infection found): A positive test result means that signs of an HIV infection were found in your sample. Limitation: You will need a follow-up test to confirm an HIV diagnosis unless you had a NAT test. Next step: If you used an at-home test, see your provider for follow-up testing. If your follow-up test is also positive, it means you have HIV. It's important to start medicines called antiretroviral therapy (ART) right away, even if you're still healthy.

• No test can find HIV immediately after infection. The window period depends on the test type and your body's response.
• A negative result does not always mean you don't have HIV—you may need a later test.
• A positive screening result requires a follow-up test to confirm an HIV diagnosis (unless a NAT test was used).
• At-home tests require careful following of instructions; results should be discussed with a provider.

What to do next

Your provider or an HIV counselor can explain your test result and let you know if you need another test.

• What type of HIV test did I have and what is its window period?
• Do I need a follow-up test?
• How often should I be tested based on my risk?
• What are my options for anonymous testing?

Evidence source

Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.

U.S. National Library of Medicine: HIV Screening Test

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