HOW IS THE TEST USED?

HOW IS THE TEST USED?

The viral load test is helpful in several areas:

* For medical researchers, the test has been used to prove that HIV is never “latent” but is always multiplying. Many people with no symptoms of AIDS and high CD4 cell counts also had high viral loads. If the virus was latent, the test wouldn’t have found any HIV in the blood.
* The test can be used for diagnosis, because it can detect a viral load a few days after HIV infection. This is better than the standard HIV (antibody) test, which can be “negative” for 2 to 6 months after HIV infection. (See Fact Sheet 102 for more information on HIV antibody testing.)
* For prognosis, viral load can help predict how long someone will stay healthy. The higher the viral load, the faster HIV disease progresses.
* For prevention, viral load predicts how easy it is to transmit HIV to someone else. The higher the viral load, the higher the risk of transmitting HIV.
* Finally, the viral load test is valuable for managing therapy, to see if antiretroviral drugs are controlling the virus. Current guidelines suggest measuring baseline (pre-treatment) viral load. A drug is “working” if it lowers viral load by at least 90% within 8 weeks. The viral load should continue to drop to less than 50 copies within 6 months. The viral load should be measured within 2 to 8 weeks after treatment is started or changed, and every 3 to 4 months after that.