HIV Tests – Different types of HIV tests and when to get tested for HIV

HIV Tests can be broadly divided into 3 different types. Each type of test looks for different components such as:

1. Actual presence of virus, if present, the amount of virus in blood (called viral load)
2. Presence of antigens and antibodies in blood
3. Presence of antibodies

Before we delve into the details of HIV tests, types and when to get tested, let’s understand few basic terms of the test.

1. Viral load – This is the amount of virus that is present in the infected person’s blood.
2. Antigen – This is typically the one that causes the immune system to respond/react. This can be the actual virus, bacteria or any other microbe or this can be anything else which may have been used in a vaccine.
3. Antibody – The antibodies are component produced by the body’s immune system. The antibody sticks itself to the antigens either to deactivate them or to mark the antigen for the immune system so that it can destroy it.

HIV Tests – types

There are mainly three types of HIV tests available.

1. NAT – Nucleic Acid Tests
2. Antigen / Antibody Tests
3. Antibody Tests

NAT – Nucleic Acid Tests

The Nucleic Acid Test aims to look for the presence of the virus and if present, in what amounts. (Viral load). The test is performed on the blood drawn from the vein.  NAT tests can be done in early stages of infection and is more expensive compared to other tests. Usually it takes few days for the results to be available when a NAT is done.

Antigen / Antibody Tests

These tests look for both antigen and antibodies in the blood. Antibodies are produced by the immune system when the body is exposed to antigens including bacteria, virus etc. In case of HIV virus, the antigen is called p24. This is produced before the antibodies develop. Currently there is a normal antigen/antibody test (blood is drawn from vein) and also a rapid antigen/antibody test (blood is drawn by pricking the finger). Results of antigen/antibody tests are obtained in less than an hour.

Antibody tests

These tests look for antibodies in the body. The presence of antibodies that are specific to the p24 antigens confirms the presence of HIV in the body. This is almost a 100% confirmative test but in order to avoid false positives, a repeat test will be recommended by the doctors after 30 to 90 days. The blood sample may be collected from a finger prick or from the vein or even oral fluid may be used to conduct the test. Results are usually obtained in less than an hour.

When to get tested for confirmed HIV results?

If you think you have come in risky contact with a possibly HIV positive person, the very first thing you need to do is ‘do not panic’. See a good gynecologist or a general physician near you immediately. If the contact period is less than 72 hours, you can be put on PEP – Post Exposure Prophylaxis. PEP prevents the virus from taking control of the body.

If it’s been over 72 hours, then most likely you need to wait for few days to get tested and to get the right result.

1. NAT – If it’s been over 10 days and less than 30 days, you can go for NAT test and it should be able to detect the presence of the virus in your body/blood.
2. Antigen/antibody test – You need to wait for 20 days after possible contraction of virus to undergo antigen/antibody test.
3. Antibody test – You need to wait for around 30 days to go for antibody test. This may vary from person to person because the time to develop antibodies may vary. It is recommended to go for an antibody test by giving a blood sample than oral fluids to get more accurate results.

The most common symptoms of HIV infection

Following are the most common symptoms of a HIV infection:

1. Fever
2. Rashes
3. Chills
4. Night sweats
5. Muscle pains
6. Sore throat
7. Swollen lymph nodes.

Note that these symptoms may vary between individuals and also the severity and the time duration by when they show up will also vary. Also you need to remember that ‘stress and anxiety’ can show up any or even all of these symptoms. So, you need to stop googling for ‘symptoms of hiv infection’ if you think you are exposed and see your gynecologist immediately.

Are women at higher risk than men in contracting HIV?

During the act of unprotected sex, exchange of bodily fluids takes place between the man and the woman. However, as the woman is the main recipient of male fluids, chances of contracting HIV even with one risky encounter with a possibly infected man are very high compared to that of men. Make sure you use protection when having intimate time with a not so familiar person or a new partner.