The concept of HIV is still stigmatized in today’s world, making it difficult for people to teach HIV testing in their regular checkups. Detection of HIV at an early stage is necessary for the treatment to begin. Antiretroviral therapy (ART) can be initiated the day one gets tested HIV positive. It will help in reducing the chances of transmission to other people. It is essential for pre-exposure prophylaxis, where the patient is required to take medication before the infection starts penetrating the whole body. Especially pregnant women must incorporate HIV testing in their pre-natal care so that essential medication can be taken to avoid transmission to the baby. In this blog, we will provide an insight into the types of tests for HIV and the most suitable option for early detection.
Types of HIV Tests
Three kinds of tests can be conducted to identify if you are HIV positive or not. The approach to be considered is “the earlier, the better.” If one has the slightest doubt, then one must get tested using any method of HIV testing explained below:
Another name for an antibody test is a serological test. HIV is directly linked with the immune system, so this test is performed to detect the number of antibodies produced with HIV infection. These antibodies can be detected in blood, saliva, or urine. This test can be conducted using two methods such as enzyme immunoassay (EIA) or rapid testing. EIA is generally conducted, which is then cross-verified using a western blot test. Rapid testing is conducted in a setting of outreach programs or clinics where immediate result is required. It provides results in a timeframe of 20 minutes only. Some of the healthcare providers offer counseling services pre and post-test to deliver details regarding transmission and prevention.
Now, the question arises when this test is applicable. The test should be conducted after detectable antibodies are developed. People make a mistakes by conducting tests after catching HIV and before the development of antibodies, which always results negatively, providing false results.
At times, antibody tests might generate false positive or false negative results. The false negative result occurs when a person conducts a test before the development of antibodies or in case their immune response is delayed. However, cross-reactivity with other antibodies might result in false positive results.
Antigens are specific proteins that are associated with HIV. Especially the p24 antigen is targeted through this test which lies on the surface of the virus. If a person is HIV positive, then this protein will be found in higher concentration. Mostly, antigen test is used with antibody tests to get comprehensive and accurate results which will be helpful in making appropriate diagnoses. This combination is known as the fourth-generation test and is most used worldwide. Rapid testing can be done in a clinical setting that provides accurate results. Positive antigen tests can be verified through western blot or nucleic acid tests. It is suggested to spend time, effort, and money on the initial stage because the whole treatment will be based on this analysis.
Antigen tests can detect the virus earlier as compared to antibody tests. The viral protein p24 exists on the structure of HIV, so whenever a body encounters the virus, then, it results in a positive.
There is a higher frequency of false positive results as it might detect the antibodies generated through other infections or medical conditions. The test might provide false negative results because of low viral load. In case the viral protein is not present in detectable quantity, then the test will show false negative results.
Nucleic Acid Test:
With the help of advanced research, the nucleic acid test (NAT) is introduced. It detects the genetics of the human immunodeficiency virus (HIV). It is the most sensitive test preferred for early detection using RNA (ribonucleic acid) or DNA (deoxyribonucleic acid). The presence of any one of the generic materials can be useful in early detection. However, HIV is an RNA virus, so it is the most common method used. NAT does not offer any sort of rapid testing for clinics or outreach programs; rather, it can only be executed in a laboratory setting.
NAT has a shorter window period as it detects the virus before the development of antibodies. It is even effective in the acute phase of the virus, which is the time when you catch infection till the time antibodies are developed.
Even though it is a sensitive test, there are chances of false negative results. It might happen due to the low viral load of the genetic material present in the virus. Technical issues can be an added reason for false results. Contrarily, false positive results can be due to contamination of the sample. It can be avoided by using proper laboratory techniques and quality control measures.
Best Test for Early Detection
As discussed in the previous section, there are three common tests available to detect human immunodeficiency virus (HIV). All these tests have their pros and cons, but the most sensitive, reliable, and accurate source is a nucleic acid test (NAT). Antibody and antigen tests are recommended to be conducted at the first stage, and if the results come positive, then those can be cross-verified using NAT. It is not preferred to be conducted at an earlier stage because of its high cost. Apart from diagnosis, NAT is also helpful in quantifying the amount of viral load to monitor and balance this number, making it undetectable.
Human immunodeficiency virus (HIV) comes along with a terror of incurable disease. This terror takes away all the courage from people to even think of reliable procedures to be followed to identify and treat the virus. With the advancement of research and technology, there are multiple methods of HIV testing available that can detect the virus at earlier stages, making it possible to minimize the viral load. HIV can be suppressed by adopting a healthy lifestyle and adhering to medications prescribed for its cure.