HIV

HIV testing can involve several types of investigations, including the examination of blood and other body fluids for the presence of the human immunodeficiency virus (HIV). HIV screening is the only way to know if the virus is present in your body. In most cases, immediate diagnosis of HIV cannot be made as it takes time for the virus to grow inside the body and produce antibodies against it. If, however, timely diagnosis is made after HIV screening, treatment can be initiated right away.

Who should get tested for HIV?

The guidelines of Centers for Disease Control and Prevention (CDC), recommend that everyone between the ages of 13 and 64 get tested for HIV at least once.

In case of the following high-risk population, testing is advised at least once a year:

• People with multiple sexual partners
• People who have had unprotected sexual contact with someone high-risk for HIV
• People who take intravenous illicit drugs
• People who have had exposure to intravenous drugs with needles or devices that were not properly sterilized
• Patients diagnosed with hepatitis or tuberculosis
• Patients diagnosed with sexually transmitted diseases including syphilis, chlamydia, herpes or gonorrhea

HIV test procedure

• Rapid tests: These are screening tests that can be done in 20 to 30 minutes. Most community hospitals are equipped with the kits for rapid HIV testing
• Laboratory test: These are the more detailed type of tests that take days to give results. For these tests, blood sample is taken by a phlebotomist for investigation

What are the types of HIV tests?

There are several types of HIV tests, including:

• Standard HIV blood tests: This investigation involves finding antibodies against the HIV about 23 to 90 days after infection. Blood sample is used to run this type of investigation.
• Antibody/antigen test: For this type of testing, both antibody and antigen are used to detect the virus. This type of test uses blood sample from vein or finger prick for running, and can be done 18 to 45 days after exposure to the virus. With newer antigen/antibody combination kits, also known as fourth generation tests, HIV can be found in 99 percent of positive cases within 13 to 42 days of exposure. This test has become the standard in most laboratories.
• Rapid blood test:This test can be performed with a drop of blood from the fingertip. Its accuracy is as good as the original antibody test but the window period for this test is longer, about 18 to 90 days.
• Nucleic acid tests (NAT):This test can be used 10 to 33 days after exposure to HIV to look for the nucleic acids present in the virus, instead of the antibodies against the virus. This test is also known as HIV RNA or viral load investigation. This is not routinely done for screening purposes. Rather, it is used by healthcare providers to check for response to treatment in people already having HIV.

What is the right time to get tested for HIV?

The right time to get tested for HIV is when you have history of high-risk exposure to the virus in the recent past. This can include cases of sexual assault or unsafe sexual encounter. Post-exposure prophylaxis (PEP) are drugs that can minimize the chances of contracting the virus, but need to be taken within three days of exposure.

For individuals not having access to PEP, getting screened for HIV is recommended in the following two weeks. Most people who are HIV-positive have detectable levels of antibodies three months after contracting the virus. Thus, if the initial test is negative, your doctor can tell you to repeat the test in three months for more accurate results.

What is the window period?

This is the waiting period for more accurate results of HIV testing. The results are inaccurate if the test is performed soon after exposure. Therefore, a small waiting time is recommended to make the results more accurate.

How long does it take to get the test results?

The rapid HIV tests can give the results within half-hour. The results for blood tests or antigen-antibody tests can take a few days. The time is even longer for NAT test.