What it measures: How much HIV is in your blood. This information helps you and your doctor make decisions about HIV treatment and determine whether the medications are working. Fewer than 50 copies of HIV per mL—about a teaspoon of blood—reads as “undetectable”; results range from undetectable up to millions of copies per mL.
When it’s used: Usually at the same time as CD4 counts—typically every few months—to monitor your HIV infection and see if any change in treatment is needed. A sudden change in viral load may call for an immediate repeat test.
How it helps: An undetectable result doesn’t mean the virus is gone for good, but it signals successful treatment and a low likelihood of worsening disease. If you are on HAART (Highly Active Antiretroviral Treatment—a potent combo of HIV-fighting drugs), an undetectable viral load is considered the best possible result. If you’ve just started treatment, this might take several months—another test in two or three months will tell for sure.
Test Tip: Even if the viral load is considered undetectable, it may occasionally bounce up to small but measurable values. These may not be cause for alarm. But persistent, detectable viral load while you’re on HAART is cause for concern: It’s a signal that your treatment isn’t controlling the virus. You and your doc need to talk about a switch.
Note: If you are not on HAART, it’s not so clear how your viral load result affects your care. Recent science has questioned whether people with higher viral loads progress (get sick) faster. Ask your doc to break down the info about your viral load so that you know how it affects your health.