HIV 1 & 2 Antibodies Test

An HIV test is used to detect HIV (Human Immunodeficiency Virus). There are many variants of HIV, but the most common types are HIV-1 and HIV-2. They cause HIV infection that affects the immune system of our body.

In advanced cases, it progresses to AIDS (Acquired Immunodeficiency Syndrome). The HIV test can also help determine whether the infection is caused by HIV-1 or HIV-2 virus.

There are high chances of HIV infection if you have unprotected sexual activity, multiple sexual partners, HIV positive mothers, use  infected needle for drugs, or receive infected blood transfusion. The most common symptoms include fever and chills, fatigue, night sweats, sudden weight loss, muscle ache, swollen lymph nodes and rashes that may last for a few days to several weeks.

Get an HIV test if you have been exposed to the mentioned activities and have symptoms. The following are the types of HIV tests available:

HIV Antibody screening tests - They are rapid tests. The test looks for a protein that the body produces within 2-8 weeks of infection.

Antigen/antibody combination test - Antigens activate our immune system, and antibodies are produced by the immune system when exposed to HIV. The test looks for both HIV antigens and antibodies in the blood.

Nucleic acid test (NAT) - It is also known as the RNA test. It detects the virus and tells us how much virus (HIV viral load) is present in the blood. It is expensive and is not used for screening. It is advised when the person is at high risk or has early symptoms of HIV infection. It can diagnose HIV after 10 days of infection.

Initially, antigen/antibody combination tests or Rapid antibody tests are advised for the screening of HIV infection. If the screening test results come positive, one more follow-up test is required to confirm the infection. Following are the confirmatory tests:

• Antibody differentiation test for HIV-1 and HIV-2
• Indirect Immunofluorescence Assay or Western Blot test
• HIV-1 nucleic acid amplification test(NAAT)
• If you find out about infection through HIV Blood tests early, you can start the treatment immediately.

India has the third-largest HIV epidemic in the world, with over 2 million HIV positive people. It is more prevalent in bisexual men, gays and sex workers. Though it affects both sexes, men are more susceptible to the infection than women in India.

Other Names of HIV Test

• HIV EIA Test
• HIV CLIA Test
• HIV Screening Test
• Third Generation Antibody Test
• Fourth Generation Antibody/Antigen Test

What does the test detect/measure, and who is this prescribed for?

The HIV test detects the presence or absence of the HIV virus, HIV antigens or HIV antibodies.

It is generally prescribed to people who are at more risk for developing HIV infection than others. The people who have:

1. Multiple sexual partners
2. Shared needles, syringes or other equipment while injecting drugs
3. Other sexually transmitted diseases such as hepatitis or tuberculosis
4. Had an infected blood transfusion
5. HIV positive mother or partner
6. Had sex for drugs or money
7. Sudden weight loss
8. Muscle ache
9. Swollen lymph nodes

It is also prescribed for:

1. Pregnant women or those planning to get pregnant
2. Bisexual men or gay

The type of test done for screening depends upon the risk factor and symptoms.

The HIV test uses a blood sample to screen HIV infection. The final confirmatory tests require a blood sample.

• The NAT and antigen/antibody combination tests require blood drawn from veins.
• The Rapid Antibody tests require a blood sample from a finger prick.

Test Preparation

The HIV test does not require fasting or any specific preparation. To collect a blood sample, blood is drawn from one of the veins of a person’s forearm. This procedure lasts for 5 minutes.

Test inclusions: What parameters are included?

The HIV test includes only one parameter, whether it’s positive or negative, in a qualitative screening test and a quantitative value in ELISA/CLIA/EIA method.

The National AIDS Control Programme has significantly helped in the reduction of new HIV infections. There are many social stigmas and myths associated with HIV that need to be addressed. Please note HIV does not spread by:

• Air or water
• Saliva, sweat or tears
• Insects or pets
• Sharing food or drinks
• Sharing room or toilets

Sexually transmitted diseases such as Hepatitis and Tuberculosis, Drug addiction, Generalised Lymphadenopathy, PUO

In laboratory HIV tests, Western Blot test and a few other tests:

The normal values, parameters, and reference ranges of the test may vary from lab to lab. Please refer to the ranges mentioned in the report and consult a doctor to understand the interpretation of lab reports.

HIV test results are reported as indeterminate, negative or positive. To understand the result, it is essential to know about the window period. You cannot detect the virus immediately after the infection. The time from when the person is infected to when the infection can be detected is called the window period.

The time interval is different for different people. It is crucial to consider the window period while screening for HIV. It ranges from 2 to 12 weeks and varies from test to test. After the initial screening test, a final follow-up test is done to confirm the HIV infection.

• Negative (or non-reactive) results on the HIV test: If the test result is negative, it means that there are no HIV antigens or antibodies in the blood. It does not require an additional follow-up test for confirmation. However, if the person has been exposed to HIV and the result is negative, it is advised to get tested again after 3 months to confirm the test results.

• Positive (or reach prevalent HIV live) results on an HIV test: If the result is positive, follow-up testing is needed to confirm the infection. If the confirmatory HIV test result is also positive, a person is considered to be HIV-positive.

• Indeterminate results on an HIV test: It occurs when the screening test is positive, but the confirmation test is negative. Doctors may ask for other tests to be sure about HIV.

For HIV, prevention is better than cure. Currently, there is no effective cure for HIV infection. If you have HIV, it will remain for life. You can only control it with proper medical care and treatment.