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HIV Screening Test

What is an HIV test?

An HIV test shows whether you are infected with HIV (human immunodeficiency virus). HIV is a virus that attacks and destroys cells in the immune system. These cells protect your body against disease-causing germs, such as bacteria and viruses. If you lose too many immune cells, your body will have trouble fighting off infections and other diseases.

There are three main types of HIV tests:

  • Antibody Test. This test looks for HIV antibodies in your blood or saliva. Your immune system makes antibodies when you are exposed to bacteria or viruses, like HIV. An HIV antibody test can determine if you have HIV from 3–12 weeks after infection. That's because it can take a few weeks or longer for your immune system to make antibodies to HIV. You may be able to do an HIV antibody test in the privacy of your home. Ask your health care provider about at-home HIV test kits.
  • HIV Antibody/Antigen Test. This test looks for HIV antibodies and antigens in the blood. An antigen is a part of a virus that triggers an immune response. If you've been exposed to HIV, antigens will show up in your blood before HIV antibodies are made. This test can usually find HIV within 2–6 weeks of infection. The HIV antibody/antigen test is one of the most common types of HIV tests.
  • HIV Viral Load. This test measures the amount of the HIV virus in the blood. It can find HIV faster than antibody and antibody/antigen tests, but it is very expensive. It is mostly used for monitoring HIV infections.

Other names: HIV antibody/antigen tests, HIV-1 and HIV-2 antibody and antigen evaluation, HIV test, human immunodeficiency virus antibody test, type 1, HIV p24 antigen test

What is it used for?

An HIV test is used to find out if you have been infected with HIV. HIV is the virus that causes AIDS (acquired immunodeficiency syndrome). Most people with HIV don't have AIDS. People with AIDS have an extremely low number of immune cells and are at risk for life-threatening illnesses, including dangerous infections, a severe type of pneumonia, and certain cancers, including Kaposi sarcoma.

If HIV is found early, you can get medicines to protect your immune system. HIV medicines may prevent you from getting AIDS.

Why do I need an HIV test?

The Centers for Disease Control and Prevention (CDC) recommends that everyone between the ages of 13 and 64 get tested for HIV at least once as part of routine health care. You may also need an HIV test if you are at higher risk for infection. HIV is mainly spread through sexual contact and blood, so you may be at a higher risk for HIV if you:

  • Are a man that has had sex with another man
  • Have had sex with an HIV-infected partner
  • Have had multiple sex partners
  • Have injected drugs, such as heroin, or shared drug needles with someone else

HIV can spread from mother to child during birth and through breast milk, so if you are pregnant your doctor may order an HIV test. There are medicines you can take during pregnancy and delivery to greatly reduce your risk of spreading the disease to your baby.

What happens during an HIV test?

You will either get a blood test in a lab, or do your own test at home.

For a blood test in a lab:

  • A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

For at home test, you will need to get a sample of saliva from your mouth or a drop of blood from your fingertip.

  • The test kit will provide instructions on how to get your sample, package it, and send it to a lab.
    • For a saliva test, you will use special spatula-like tool to take a swab from your mouth.
    • For a fingertip antibody blood test, you will use a special tool to prick your finger and collect a sample of blood.

For more information on at-home testing, talk to your health care provider.

Will I need to do anything to prepare for the test?

You don't need any special preparations for an HIV test. But you should talk with a counselor before and/or after your test so you can better understand what the results mean and your treatment options if you are diagnosed with HIV.

Are there any risks to the test?

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

What do the results mean?

If your result is negative, it can mean you don't have HIV. A negative result may also mean you have HIV but it's too soon to tell. It can take a few weeks for HIV antibodies and antigens to show up in your body. If your result is negative, your health care provider may order additional HIV tests at a later date.

If your result is positive, you will get a follow-up test to confirm the diagnosis. If both tests are positive, it means you have HIV. It does not mean you have AIDS. While there is no cure for HIV, there are better treatments available now than in the past. Today, people with HIV are living longer, with a better quality of life than ever before. If you are living with HIV, it's important to see your health care provider regularly.

References

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The medical information provided is for informational purposes only, and is not to be used as a substitute for professional medical advice, diagnosis or treatment. Please contact your health care provider with questions you may have regarding medical conditions or the interpretation of test results.

In the event of a medical emergency, call 911 immediately.