Serum Anti-HIV – 1 & 2

Specimen Required

3-5cc Clotted Blood or Serum

Fasting Required

Purpose of the Test

To determine if you are infected with human immunodeficiency virus (HIV)

When this test is required

Testing for HIV should be requested if you think you may have been exposed to HIV (for example if a sexual partner is HIV positive). Testing is also recommended if: You are sexually active (three or more sexual partners in the last 12 months). You received a blood transfusion before 1985 (since 1985 all blood donated in the UK and the US is tested for HIV and infection by transfusion is now exceptionally rare). You are uncertain about your partner’s sexual behaviour with others. You are a male who has had sex with another male. You have used street drugs by injection, especially when sharing needles or other equipment. You have a sexually transmitted disease (STD) or an infection with hepatitis B or C. You are a health care worker with direct exposure to blood at work. You are pregnant. You are a woman who wants to make sure you are not infected with HIV before becoming pregnant. You must have a test if you want to become a blood donor, use your sperm for artificial insemination, have an egg implantation or adopt a child.In the UK the HIV test is free, and widely available as a routine test. You can be tested by your doctor, at any clinic dealing with STDs such as Genito-Urinary Medicine (GUM) clinics, at Terrence Higgins Trust Fastest centres, at antenatal or termination of pregnancy clinics and at drug treatment or needle-exchange centres.Test results on blood samples should not take longer than three days. While-you-wait (so-called “point-of-care”) testing using a finger prick test can give a result in a few minutes. However, these tests can give false negative as well as false positive results. Positives should always be confirmed with tests on blood taken from a vein.Testing can be carried out anonymously and your GP is not informed of the clinic result without your permission. Clinic staff will give advice about informing sexual partners if your test is positive.

What the Test Detects

Human immunodeficiency virus (HIV) infects the cells of a person’s immune system and is the cause of AIDS (acquired immunodeficiency syndrome).When a person becomes infected with HIV, through exposure to the blood or body fluids of an infected individual, the virus begins to reproduce very rapidly. So, during the first few weeks of infection, the amount of virus (viral load) in the blood can be quite high.The immune system…Human immunodeficiency virus (HIV) infects the cells of a person’s immune system and is the cause of AIDS (acquired immunodeficiency syndrome).When a person becomes infected with HIV, through exposure to the blood or body fluids of an infected individual, the virus begins to reproduce very rapidly. So, during the first few weeks of infection, the amount of virus (viral load) in the blood can be quite high.The immune system responds by producing antibodies directed against the virus and these begin to be detected in the blood around 3-4 weeks after exposure to the virus. As the level of HIV antibody increases, the viral load in the blood decreases.This early HIV infection may cause no symptoms or sometimes a flu-like or glandular fever-type illness. The only way to determine whether a person has been infected is through HIV testing. Modern HIV screening tests detect HIV antigens (parts of the virus itself, usually a protein called the p24 antigen) and/or antibodies produced in response to an HIV infection.Two main test types are available for HIV screening:Combination HIV antibody and HIV antigen test— this is the recommended screening test for HIV and is available only as a blood test. By detecting both antibody and antigen, the combination test increases the likelihood that an infection is detected soon after exposure. These tests can detect HIV infections in most people by 2-6 weeks after exposure.HIV antibody testing— This test takes a little longer to become positive after an exposure but can be carried out on blood or oral fluid. HIV antibody tests can detect infections in most people 3-12 weeks after exposure.How is the sample collected for testing?Blood is taken through a needle placed in a vein in your arm or sometimes by finger prick. Saliva is collected using a spatula with an absorbent pad on its tip which is swept around between the cheeks and the upper and lower gums.Is any test preparation needed to ensure the quality of the sample?No test preparation is needed. See MoreSee Less

Preparation for the Test

None

Sample Requirements

A blood sample collected from a vein in your arm or from a fingerprick; some tests can also be performed on urine or saliva (spit)

Additional Notes

HIV antigen/antibody testing will not detect HIV immediately after exposure, during the window before the development of a high level of virus and/or antibodies in the blood. Your result may be negative despite the fact that you are infected – a false negative interpretation. Because of this, repeat testing is important. You should have another HIV test at least 2-3 months from the time of a possible exposure to the virus.

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