People can live with HIV for years before having any symptoms. The only way to be sure is to have an HIV test. Find out where to test and how the test will be carried out read below:-
A blood test is the usual way HIV is detected. An HIV test can work by detecting:
Testing for HIV is done in two stages. First, a primary test is done. If it is positive, then the test is repeated to check for false positives. If the primary test is positive twice, then the sample is tested with a second, more specific, confirmatory test to make certain that the primary test isn't reacting to an infection other than HIV.
Generally referred to as ELISA (enzyme-linked immunosorbent assay) or, alternatively, EIA (enzyme immunoassay), these tests detect HIV antibodies, which the body starts producing between 2 and 12 weeks after becoming infected with HIV. Current HIV antibody tests can detect antibodies as early as 3 weeks after exposure, which is faster than the 1st generation of antibody tests. Current HIV antibody tests are often referred to as 2nd generation (detecting IgG antibodies), 3rd generation (detecting both IgM and IgG antibodies), and 4th generation (detecting both HIV antibody and the p24 antigen, which comes directly from the HIV virus). All positive HIV antibody test results should be confirmed with a Western blot, DNA PCR Antigen Test or a Real Time HIV viral load test. Some HIV antibody tests will not detect HIV-2 (a strain of HIV that is found in western Africa) and some more uncommon strains of HIV-1. If HIV-2 infection is suspected, it is important to know whether the antibody test used is designed to detect both HIV-1 and HIV-2.
Results from most ELISA tests and confirmatory Western blot tests are usually available within 2 to 14 days.
Rapid HIV Test
Using technology similar to that of an ELISA, a rapid test produces results in approximately 20 minutes. Two types of rapid tests are available now. One uses blood; in this case, a clinician pricks your finger with a small needle and takes a few drops of your blood. The other uses oral fluids and is very similar to the oral fluid test described above.
There are two possible outcomes with this test: negative (meaning that the test does not detect any HIV antibodies) or "preliminary positive." In the case of preliminary positive, the rapid HIV test shows an HIV-positive result, but, as with the ELISA test, that result must be confirmed with a second test such as a Western blot or a second rapid test from a different manufacturer. If the result is preliminary positive, the provider will discuss what this means with the client, including the importance of practicing safer sex and taking other precautions until the confirmation test results come back, and will schedule a time for the client to receive confirmatory results.
The ELISA test is designed to be highly sensitive, that is, to miss as few HIV infections as possible. The downside of the high sensitivity is that the ELISA may produce a small number of false-positive results. This usually is caused by the presence of antibodies to other diseases that the ELISA mistakenly recognizes as antibodies to HIV. For this reason, it is important to supplement both positive ELISA and rapid antibody results with a confirmatory test, such as a Western blot, that is less sensitive but more specific, that is, one that has a lower rate of yielding a false-positive result. Sometimes, a rapid antibody test is confirmed with a second rapid test from a different manufacturer.
The Western blot is the most common test used to confirm positive results from an ELISA or rapid HIV test. It generally is used only as a confirmatory test because it is difficult to perform and requires highly technical skills. Its advantage, however, is that it is less likely to give a false-positive result because it can more effectively distinguish HIV antibodies from other antibodies. However, the Western blot can yield inconclusive results in some samples.
Indirect Fluorescent Antibody (IFA)
The indirect fluorescent antibody (IFA) test also detects antibodies made to fight an HIV infection. As with the Western blot, the IFA test is used to confirm the results of an ELISA. However, it is more expensive than a Western blot test.
PCR stands for Polymerase Chain Reaction. PCR is a technique to look for unique DNA. PCR for the HIV virus looks for DNA of the HIV virus. PCR for the gene of cystic fibrosis looks for that DNA sequence unique for cystic fibrosis.
The standard AIDS test is an Elisa test, which tests for the antibodies your body makes for the AIDS virus. This test is the standard test used by hospitals and blood banks in America and the world. Positive tests are confirmed with a second test called the Western blot, which also analyzes the body's antibody response. The Elisa test is usually positive 3 months after infection with the HIV virus.
The advantage of the PCR test is that it is a direct test for the presence of the DNA HIV virus. If you are infected, the DNA of the AIDS virus is present in your blood. This test can pick up HIV infection before the Elisa test turns positive.
The PCR test has a 95% confidence level for detecting HIV infection after 28 days.
HIV-1 Proviral DNA Detection
The detection of cell associated Human Immunodeficiency Proviral DNA by polymerase chain reaction (PCR) amplification is one of the most sensitive non-serologic methods for confirming HIV infection. In addition to HIV culture, this assay is recommended for confirming HIV infection in the neonate. HIV DNA PCR may also be used as a supplemental test to determine the significance of an indeterminate HIV Western Blot serology result.
Polymerase Chain Reaction (PCR) is superior to any other test for the following reason: It is a direct detection method, which searches and detects the actual pathogen's nucleic acids. In contrast, the ELISA and the Western Blot detect only the body's immunologic response.
HIV RNA Viral Load Test
You will likely hear this test called a "viral load," "PCR," or "RNA" test. In the public health community, it is also referred to as HIV NAAT (nucleic acid amplification testing). The viral load test usually is used by clinicians to determine whether antiretroviral medications are working to suppress viral replication in HIV-infected persons taking medication. Unlike the previously mentioned HIV antibody tests, these types of tests detect the genetic material (RNA) of the virus rather than antibodies to HIV.
Quantification of human immunodeficiency virus type-1 (HIV-1) proviral DNA is increasingly used to measure the HIV-1 cellular reservoirs, a helpful marker to evaluate the efficacy of anti-HIV Support regimens in HIV-1–infected individuals. Furthermore, the proviral DNA load represents a specific marker for the early diagnosis of perinatal HIV-1 infection and might be predictive of HIV-1 disease progression independently of plasma HIV-1 RNA levels and CD4+ T-cell counts. The high degree of genetic variability of HIV-1 poses a serious challenge for the design of a universal quantitative assay capable of detecting all the genetic subtypes within the main (M) HIV- 1 group with similar efficiency.
Highly sensitive real-time PCR protocol allows for the correct quantification of virtually all group-M HIV-1 strains with a higher degree of accuracy compared with other methods.
The protocol involves three stages, namely DNA extraction/lysis, cellular DNA quantification and HIV-1 proviral load assessment. Owing to the robustness of the PCR design, this assay can be performed on crude cellular extracts, and therefore it may be suitable for the routine analysis of clinical samples even in developing countries. An accurate quantification
of the HIV-1 proviral load can be achieved within 1 day from blood withdrawal.
In HIV-1 infection, the determination of the number of cell associated HIV-1 DNA copies (HIV-1 proviral load) by real-time PCR is employed not only for research purposes but also for evaluating the effects of anti-HIV therapy on the viral reservoirs. Furthermore, a high HIV-1 proviral DNA load following primary infection has been suggested to be predictive of rapid disease progression independently of plasma viremia and CD4+T-cell counts.
Real-time PCR offers several important advantages over conventional quantitative PCR methods by substantially reducing labor and costs because a single PCR run is sufficient to accurately quantify target DNA without any post-amplification steps. Moreover, the absence of post amplification manipulation steps greatly reduces the risk of inter-sample contamination and eliminates the need for employing radioactive labels or other hazardous reagents. Finally, by virtue of its high-throughput format, this system is well suited for automatization and use in the routine clinical diagnostic setting. Here, we developed a real-time PCR protocol for the quantification of the HIV-1 DNA load that can be applied equally well to experimental and clinical settings. Although a very limited number of variant isolates may still escape accurate quantification, this protocol is able to correctly measure HIV-1 DNA from a wide panel of viral isolates of diverse genetic subtypes.