Viral load

  • A viral load test measures the amount of HIV in the blood.
  • The amount of virus is counted in the form of 'copies' per millilitre (ml) of blood. Undetectable viral load is a treatment goal. 10,000 copies per ml is considered a low number; over 100,000 copies per ml is considered high and an indication to begin antiretroviral therapy or change the current regimen.
  • Viral load changes are so large that they are sometimes quantified using the powers of ten, or log scale (scientific notation). A 1-log change represents a ten-fold change, a 2-log change is a one hundred-fold change and notated as 102.
  • Repeated viral load tests can vary by a factor of three. An increase in viral load would not be considered meaningful unless the result was at least three times greater than the last viral load result. A decrease in viral load is considered significant when it is less than one-third of the previous result.
  • Each test has a limit below which it cannot detect HIV's genetic material. This is known as the limit of detection, or undetectable viral load. This level is usually 50 copies/ml. Ultra-sensitive tests exist that can detect as low as 5 copies/ml.
  • Undetectable viral load does not indicate absence of HIV; only that the amount of virus present is not detectable using the technology available where the test is done.
  • Viral load may be used to diagnose acute HIV infection before seroconversion, although there will be a certain number of false positive results.
  • Viral load rises after an infection or vaccination (such as a flu shot).
  • The lower a person's viral load, the less likely they are to become sick in the near future.
  • When monitoring viral load, the same test and laboratory technique should be used. Results will vary according to the type of test used.
Community Consensus Statement on Access to HIV Treatment and its Use for Prevention

Together, we can make it happen

We can end HIV soon if people have equal access to HIV drugs as treatment and as PrEP, and have free choice over whether to take them.

Launched today, the Community Consensus Statement is a basic set of principles aimed at making sure that happens.

The Community Consensus Statement is a joint initiative of AVAC, EATG, MSMGF, GNP+, HIV i-Base, the International HIV/AIDS Alliance, ITPC and NAM/aidsmap

This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.

NAM’s information is intended to support, rather than replace, consultation with a healthcare professional. Talk to your doctor or another member of your healthcare team for advice tailored to your situation.