Blood work:
Two common tests to use for
monitoring HIV disease

January 2008     View PDF     En español

How often should viral loads be tested?

At first, two viral load tests should be taken about 2–4 weeks apart to establish a baseline level. After that, tests should be repeated every 3–4 months along with CD4 cell counts. Because other infections that you may have can briefly cause higher HIV levels, a sudden rise in viral load should be checked with another test 2–4 weeks later.

People should generally avoid having viral load tests done during an active infection (like a cold or flu), after routine vaccinations (like flu or tetanus) or during flare-ups of infections (like a cold sore). These factors can all cause HIV levels to increase 10 to 100 times, but usually returns to normal within a few weeks after a vaccination or the end of the infection.

Viral load tests should be done more often when making decisions about treatment. A test should also be done 3–4 weeks after starting or changing therapies. Because the tests can vary slightly in their results, people using a specific test should continue to use that test to get accurate results and trends over time.