Getting
Tested 
Viral load is usually reported as copies per millilitre of blood plasma (copies/mL). Viral load levels can range from less than 50 copies/mL to 20 million copies/mL and higher. Click here for more information on tests Changes in viral load are often reported as logarithmic or ‘log changes'. This is a mathematical term that refers to a change in the value of what is being measured by a factor of ten. For example, if the initial viral load was 20,000 copies/mL, then a one log increase equals a ten fold (ten times) increase or 200,000 copies/mL. (The effect is the same as adding one zero to the original value). An increase of two logs equals a 100 fold (100 times) increase or 2,000,000 copies /mL. (The effect of adding two zeros to the original value). In the same way, a one log decrease from the starting point of 20,000 copies/mL means that the viral load has dropped to 2,000 copies/mL. (The effect is the same as subtracting one zero from the original value). A two log decrease would indicate that viral load is now 200 copies/mL (subtract two zeros from the original value). For help in calculating log values from RNA copies / mL please click here Understanding the Results Viral load measurements can assist doctors and people with HIV in deciding when to start antiHIV treatment and help them assess whether treatment is working or not. This can be vital in managing HIV therapy options. However, results of viral load tests can be interpreted differently by different doctors and HIV positive individuals. To help them decide what course of action to take, the National Institute of Health (NIH) in the US has developed some guidelines on when to initiate or alter antiviral therapy. The main principals in the NIH document for interpreting viral load tests are:


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