HIV Screening: Tests That Diagnose HIV

Getting an HIV test is the only way to know if you have the incurable disease. Getting an early test may turn up negative even though you are infected. Several types of tests check your blood or body fluids to see if you’re infected.

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Most of these tests can’t detect HIV at its early stage because it takes time for your body to make antibodies or for enough virus to grow inside you. It may take up to 6 months before you’ll see a positive result. If you have the virus, you can start treatment to help you live a long and full life. You can also take precautions so that you don’t pass HIV to other people.

Antibody Screening Tests

These tests examines your body for a kind of protein it makes in response to the HIV infection, 2-8 weeks later. They’re also called immunoassay or ELISA tests. They’re very accurate, but they won’t catch early infections.

A technician will take a small blood sample for testing. Some immunoassay tests also check your urine or fluids from your mouth, but there are no much antibodies in these, so you may not get a positive result even if you’re infected – this is called false negative.

Rapid versions of these blood and oral fluid tests can give results in under 30 minutes, however, they may give false negatives results too.

Antibody/Antigen Combination Tests

The CDC recommends these blood tests to detect HIV. These tests can detect HIV as soon as 20 days earlier than antibody screening tests. They examine samples for HIV antigen, a protein called p24 that’s part of the virus that shows up 2-4 weeks after infection, as well as HIV antibodies. A rapid antibody/antigen test can give you results in 20 minutes.

READ ALSO: Early Symptoms of HIV: Symptoms in Men and Women

RNA Test

This looks for the virus itself and can diagnose HIV about 10 days after you’ve been exposed. It’s expensive, though, so it’s usually not the first test. On the other hand if you’re at high risk and you have flu-like symptoms, your doctor may want to use it.

In-Home Test Kits

Two kits are available. Ensure the one you choose is approved by FDA. One option is to prick your finger to get a small blood sample that you send to a lab. You call to get your result within a few business days, and it’s anonymous (you don’t have to give your name). If it’s positive, the lab will also perform a follow-up test.

For the other, you’ll swab your upper and lower gums and test the sample in a vial. You get a result in 20 minutes. Maybe 1 in 12 people get a false negative from this test. You should get a lab test of your blood if it’s positive.

Results and Follow-up Tests

A positive result means there were traces of HIV. If you had a rapid test, you should get a standard lab test to confirm it. If you had a lab test, more thorough tests on your blood sample can help confirm the diagnosis:

  • Antibody differentiation, between HIV-1 and HIV-2
  • Western blot or indirect immunofluorescence assay
  • HIV-1 nucleic acid test, which looks for the virus itself
  • RNA test

If you got an HIV test within the first 3 months after you could have been infected and it was negative, perform another test at 6 months to be certain.

When Should You Get Tested?

You could have an HIV infection if you:

  • Have had several sexual partners
  • Had unprotected sex with someone whose sexual history you don’t know
  • Injected drugs with a needle, syringe, or other equipment someone else had used first
  • Getting tested for tuberculosis or any sexually transmitted disease, including herpes and hepatitis
  • Have had sex for drugs or money
  • Had sex with someone who has a history of any of these

Pregnant women should also get tested.


Disclaimer: The content provided on is purely informative and educational in nature and should not be interpreted as medical advice. Please use the content only in consultation with an appropriate certified medical doctor or healthcare professional.

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