The viral load measures the amount of HIV in your blood. There are different techniques to do this:
A Polymerase chain reaction (PCR) method uses an enzyme to multiply HIV in the blood sample. After a chemical reaction that marks the virus. Markers are measured and used to calculate the amount of virus. The Roche and Abbott group produce this type of assay.
O BDNA method (Branched DNA) combines a material that results in "light off" with the sample. This material connects with the particles of HIV. The amount of light is measured and converted to a viral count. Bayer produces this test.
O NASBA (nUcleic umcid sEquence bThe amplification method) amplifies viral proteins to derive a count. It is manufactured by biomérieux.
Different test methods often give different results for the same sample. Because the tests are different, you should always use the same type of test to measure your viral load over time.
Viral loads are generally reported as copies of HIV per milliliter of blood. The test count reaches up to about 1 million copies and is always being improved to be more sensitive. The first test bDNA media up to 10.000 copies. Current tests detect up to a minimum of 20 copies. The ultra-sensitive tests used for research purposes detect up to less than 5 copies of viral RNA per milliliter of blood.
The best viral load test result is "undetectable." That does not mean there is no virus in your blood; it just means that there is not enough virus quantity for the test in use to find and count. With the first undetectable viral load of tests was "," and it meant up to 9.999 copies! "Non-detectable" depends on the sensitivity of the test used on your blood sample.
The first viral load tests used all frozen blood samples. Good results were obtained using dry samples. This will reduce costs with freezers and shipping.
How the test is used?
The test is useful in several areas:
- To the medical researchers, the test showed that HIV is never “latent” but is always multiplying. Many people without symptoms of AIDS and with high CD4 cell counts also had high levels of viral load. If the virus were latent, the test would not have found any HIV particles in the blood.
- For prognosis, Viral load can help predict how long someone will stay healthy. The higher the HIV viral load, the faster the progression of the disease.
- To prevention, Viral load predicts how easy it is to pass HIV on to another person. The higher the viral load, the greater the risk of HIV transmission.
- For the management of therapy , The test shows whether the treatment can control the virus throughout its replication cycle. Current guidelines (Fact Sheet 404) Suggest baseline (pretreatment) measurement of viral load. The treatment works by lowering the viral load level by at least 90% within 8 weeks. The viral load should continue to fall to below 40 copies within 6 months (after I suggest this reading see this link and note that, among so many things, it is absurd to deny work to a person living with HIV or AIDS). The viral load should be measured within 2 to 8 weeks after the start of treatment or if treatment has been changed. It should be monitored every 6 months after patients with good adherence reach an undetectable viral load and are clinically stable in their treatment for 2 or 3 years. According to the guidelines, treatment failure is indicated by a confirmed viral load above 200 copies.
How are changes in viral load measured?
Repeated tests of the same blood sample may give results that vary by an 3 factor. This means that a significant change would be a Less than one third ou
An increase in More than 3 times Compared to the previous test result. For example, a change from 200.000 to 600.000 is within the normal variability of the test. A drop from 50.000 to 10.000 would be significant. The most important change is to reach undetectable viral load.
Viral load changes are often described as "records" that change. This refers to scientific notation, which uses 10 powers. For example, a fall of 2-log is a drop of 102 or 100 times. One drop from 60.000 to 600 would be an 2-log drop.
Recently, researchers have observed that the viral load of many patients sometimes went from undetectable to a low level (usually less than 500) and then went undetectable again. These “blipes” do not indicate a failure in ART or that the virus is developing resistance.
What do the numbers mean?
There are no "magic" numbers for viral loads. We don't know how long you will remain healthy with any viral load. All we know so far is that the lowest viral load achieved is the best situation and seems to mean a life longer and healthier.
This section was edited and the link it misinformation will removdo
Treatment guidelines (see Fact Sheet 404) Suggest that all HIV-positive people receive treatment. For patients with viral load above 100.000, there is urgency for treatment. As was confirmed by the Study Partner, no HIV infection among partners with complete viral suppression of viral load on treatment as prevention
Translator's note. I was forced to revise this paragraph because, unfortunately, not even in the sites "1º world" is no sense of responsibility to simply update a now mistaken paragraph that read: Some people may think que if viral Their load is undetectable, They can 't pass the HIV virus to another person. This is not true. There is the "safe" level of viral load. Although the risk is less, you can pass HIV to another person even if your viral load is undetectable.
Some people may think that if their viral load is undetectable, they can not transmit the HIV virus to someone else. This is not true. There is no "safe" level of viral load. Although the risk is lower, you can pass HIV to another person even if your undetectable viral load
There are problems with the viral load test?
There are some concerns with the viral load test:
- About only 2% of HIV in your body is in the blood. The viral load test does not measure how much of HIV is in body tissues such as lymph nodes, spleen or in the central or peripheral nervous system. HIV levels in lymphoid tissue and semen fall when blood levels go down but not at the same time Or at the same rate.
- The results of the viral load test may be high if your body is fighting an infection or if you have just received an immunization (such as the flu). You should not have blood drawn for a viral load test within 4 weeks after any infection or immunization.
Translated by Claudio Souza's original Viral Load Tests
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