The HIV antibody test are the most suitable test for proper diagnosis of HIV among adults. Antibody test are affordable and incredibly correct. The ELISA antibody test (enzyme-linked immunoabsorbent) also referred to as EIA (enzyme immunoassay) was the initial HIV test being widespread.
Just how do antibody tests deliver the results?
When an individual have been infected with HIV, their entire body reacts by generating unique proteins that battles the infection, known as antibodies. A HIV antibody test searches for these antibodies in blood, saliva or urine. If antibodies to HIV are discovered, it indicates that an individual have contracted HIV. There are only two exceptions for this rule:
Infants given birth to a HIV infected mother retain their mother's antibodies for approximately eighteen months, which suggests they will test positive upon a HIV antibody test, even if they are in fact HIV negative. Generally infants who're born to HIV positive mothers obtain a PCR test (see below) after birth.
Some individuals who have taken part in HIV vaccine studies might have HIV antibodies even if they're not have contracted the virus.
A number of people produce noticeable HIV antibodies within 6 to 12 weeks after exposed to the HIV virus. In extremely unusual cases, their can be a 6 months period, and there are almost always very specific causes of antibodies developing so late for instance other auto-immune conditions. It's extremely unlikely that somebody would take more time than Six months in order to develop antibodies.
A window period of 3 month?
The 'window period' is actually a term used to explain the time period between HIV infection and the production of antibodies. During this period, an antibody test can provide a 'false negative' end result, meaning the test is going to be negative, despite the fact that an individual have contracted HIV. To prevent incorrect negative results, a second test are suggested after 3 months of possible contact with a HIV infected person..
A negative test at 3 months will more often than not, suggest that an individual have not been infected with HIV. Somebody who is tested and continues to be negative after 6 months, and have not been at risk of HIV infection in the meantime, means they are not infected with HIV.
It is extremely important to notice that if an individual is infected with HIV, they could still transmit the virus to others throughout the window period.
How correct are antibody tests?
Antibody tests are absolutely accurate when it comes to detecting the existence of HIV antibodies. ELISA tests are unquestionably sensitive and therefore will detect a small amount of HIV antibody. This higher level of sensitivity however, means that their specificity (ability to separate HIV antibodies from other antibodies) is marginally reduced. There is for that reason a really modest chance that a result could come back as 'false positive'.
A false positive result implies that even though an individual might not be infected with HIV, their antibody test may come back positive. All positive test results are followed up by using a confirmatory test, for example:
A Western blot assay - One of the oldest but most precise confirmatory antibody tests. It really is complex to manage and may even generate indeterminate results if an individual carries a transitory infection with a different virus.
An indirect immunofluorescence assay - Like the Western blot, nevertheless it relies on a microscope to detect HIV antibodies.
A line immunoassay - Widely used in the European Union. Minimizes the risk of sample contamination and it is as precise as the Western Blot test.
A 2nd ELISA - In resource-poor settings with comparatively high frequency, a 2nd ELISA test are useful to verify an analysis. The 2nd test will often be a various commercial manufacturer and make use of an alternative technique of recognition to the first.
When two tests are bundled, the possibility of obtaining an incorrect result can be lower than.1%.
Rapid HIV Test
123 Rapid Home Test ( HIV-1/2)
These HIV tests use exactly the same technologies as ELISA tests, but rather then submitting the sample to the clinical for being analysed, the rapid home test generates a results within just Twenty minutes.
Rapid HIV home tests will use either a blood sample or oral fluids. They are really simple to use and don't require any laboratory facilities or professional staff.
All positive outcomes from a rapid HIV test must be followed up by using a confirmatory test, the final results usually takes from a couple of days to a few weeks.
Antigen test (P24 test)
Antigens will be the substances found in a foreign body or germ that result in the production of antibodies in the entire body. The antigen found in HIV that most commonly brings about an antibody reaction is the protein P24. At the beginning of a HIV infection, P24 is produced in excess and will be detected in the blood serum (even after HIV becomes fully established in the body it will eventually diminish to undetectable concentrations).
P24 antigen tests usually are not used in common HIV diagnostic purposes, as they have a very low level of sensitivity and they only work prior to antibodies are produced in the period right after HIV infection. They are now in most cases utilised as a component of 'fourth generation' tests.
Fourth generation tests
The most up to date HIV tests combine P24 antigen tests together with regular antibody tests to scale back the 'diagnostic window'. Screening for noticeable antibodies and P24 antigen at the same time has the main advantage of enabling earlier and more precise HIV detection.
In the USA, fourth generation tests will be the main suggestion for HIV testing among people, but aren't provided by all testing sites. In June 2010, the FDA approved the first fourth generation test in the USA.
A PCR test (Polymerase Chain Reaction test) can recognize the genetic substance of HIV instead of the antibodies of the virus, and therefore can determine HIV in the blood in just 2 or 3 weeks of an infection. The test is also referred to as a HIV NAAT (nucleic acid amplification tests) or a viral load test.
Babies born to HIV positive parents usually are tested by using a PCR test simply because they sustain their mother's antibodies for a number of months, making an antibody test incorrect. Blood supplies are generally in most developed nations around the world, screened for HIV using PCR tests. However, they aren't usually used to test for HIV in men and women, because they are very costly and much more complex to manage and interpret than the regular antibody test.
HIV home screening and HIV home testing
It is usually suggested that the HIV test is performed by a professional medical, However, in many countries home screening and home testing kits are readily available. The quality if this home test kits have improved, and are as safe as the home sampling test and clinical test.
Sampling at Home
Using a home sampling kit, an individual can take a small sample (often a blood sample) and mail it to the clinical for screening. They're able to phone up for the final results a couple of days afterwards. If the final result is positive then a qualified counsellor will give you emotional assistance and recommendations. The most important benefits of home sampling are convenience, quickness, personal privacy and anonymity.