Viral load tests which essentially count the number of HIV particles in a patient s circulation are routinely used to assess the status of an HIV patient. This allows them to recommend optimal modes of therapy and make more accurate predictions of the future course of the infection. The newer test has largely replaced the CD4 T-cell count, an older assay used to measure immune function in HIV positive patients.
However, a new analysis published in the journal BMJ says that CD4 testing is actually more cost-effective than the viral load assay. In a trial in Uganda, researchers randomized over 1,000 patients: Some received at-home clinical monitoring weekly, while another group also underwent quarterly CD4 tests, and the remainder had both forms of monitoring in addition to quarterly viral load testing. Researchers from the University of California-San Francisco analyzed the data and found that, for one additional year of healthy life, CD4 T-cell counts cost $174, while the price rose to more than $5,000 when viral load monitoring was added to the mix.
Lead author Dr. James Kahn says that viral load monitoring is extremely expensive, so that if you want to spend money well, you appear better off spending it on antiretroviral drugs.
There is, however, one caveat. As ACSH's Dr. Josh Bloom points out, CD4 cell counts may be more cost-effective, but clinically, viral load monitoring may still have the upper hand. Unlike viral load testing, he says, CD4 cell counts won t tell you much about infectivity, because it s possible to have a normal CD4 cell count yet still be HIV positive.