Routine HIV Testing

Testing for Patients with HIV/AIDS

HIV is a life-long infection that requires continuous monitoring and treatment. Monitoring HIV infection and its progression to AIDS involves the following types of tests:

• Viral load and T-cell/CD4+ counts measure how much HIV is in the blood and help determine how quickly HIV/AIDS is progressing. These tests are used as guidelines for when to begin and change antiretroviral therapy.
• Resistance testing indicates if HIV has developed resistance to a particular antiretroviral drug. This test helps the physician decide which antiretroviral medications to prescribe and when to change medication.
• Blood tests are done to evaluate the presence of HIV-related opportunistic infections.

Viral Load

A viral load test provides a measure of the amount of HIV in the blood, specifically the number of copies of viral RNA per one milliliter (mL or cc) of blood. Viral loads in patients infected with HIV can range from undetectable to more than a million copies per mL. These tests are not sensitive enough to detect viral loads lower than about 25 copies per mL. Therefore, even though an undetectable viral load is a very good sign, it does not mean that the patient is HIV-negative. It just means that there is not enough virus in the blood to be detected.

There are number of viral load tests available and patients should discuss the options with their health care provider. It is important that patients stick with one kind of test over time to be sure that changes in the viral load test reflect actual changes in the blood and not differences between the tests.