An HIV test is a test that shows if a person has been infected with HIV (the human immunodeficiency virus). HIV is a virus that attacks and destroys the cells of the immune system. These cells protect the body against germs that cause diseases, for example, bacteria and viruses. When a person loses too many immune cells, their body has difficulty fighting infections and other diseases.
There are three main types of HIV tests:
Antibody test. This test tries to detect antibodies against HIV in the blood or saliva. The immune system produces antibodies when a person is exposed to bacteria or viruses such as HIV. The HIV antibody test can find out if a person has HIV 3 to 12 weeks after the infection. That's because the immune system can take several weeks or more to produce antibodies to HIV. You may be able to get an HIV antibody test in the privacy of your home. Ask your doctor or health professional about HIV home test kits.
Test for antibodies and antigens against HIV. This test tries to detect antibodies and antigens against HIV in the blood. An antigen is a part of a virus, which triggers an immune response. When a person has been exposed to HIV, antigens appear in the blood before the body produces antibodies to HIV. This test usually detects HIV 2 to 6 weeks after infection. Antibody and antigen testing against HIV is one of the most common types of HIV tests.
Viral load of HIV This test measures the level of HIV in the blood. It can detect HIV faster than antibody and antigen tests, but it is very expensive. It is mainly used to monitor HIV infections.
Other names: HIV antibody and antigen tests; evaluation of HIV-1 and HIV-2 antigens and antibodies; HIV test; test for antibodies against the human immunodeficiency virus type 1; HIV p24 antigen test
For what do you use it?
The HIV test is used to find out if a person has been infected with HIV. HIV is the virus that causes AIDS (acquired immunodeficiency syndrome). Most people with HIV do not have AIDS. People with AIDS have a very low number of immune cells and are at risk of getting life-threatening diseases, for example, dangerous infections, a serious type of pneumonia and certain types of cancer, such as Kaposi's sarcoma.
If HIV is detected early, there are medications to protect the immune system. Anti-HIV drugs can prevent AIDS.
Why do I need an HIV test?
The Centers for Disease Control and Prevention (CDC) recommends that everyone 13 and 64 years old be tested for HIV at least once as part of routine medical care. HIV testing may also be necessary if a person has a higher risk of infection. HIV is transmitted primarily through sexual contact and through the blood, so you may be at increased risk of contracting HIV if:
- He is a man who has had sex with another man
- Have had sex with a person infected with HIV
- He has had many sexual partners
- He has injected drugs like heroin, or has shared drug needles with another person
- HIV can be passed from mother to child during labor and through breast milk, so if you are pregnant, your doctor may ask for an HIV test. There are medications that can be taken during pregnancy and childbirth to greatly reduce the risk of transmitting the disease to the baby.
What happens during an HIV test?
A blood test is done in a laboratory or you are tested at home.
Blood test in a laboratory:
A doctor or health professional takes a blood sample from a vein in one arm using a small needle. After inserting the needle, remove a small amount of blood and place it in a test tube or vial. You may feel mild discomfort when the needle is inserted or removed, but the procedure usually takes less than five minutes.
For the home test, you need a sample of saliva from your mouth or a drop of blood from your fingertip.
The test kit has instructions on how to obtain, package and send the sample to a laboratory.
For the saliva test, a special device resembling a small spatula is used to obtain a saliva sample from the mouth.
For the blood test, a special device is used to obtain a sample by pricking the fingertip of a finger.