Introduction of the TaqMan Viral-Load Assay: Progress or Peril?

The goal of antiretroviral therapy (ART) is to suppress viral loads to undetectable levels (<50 copies/mL) on our most sensitive assays. Most clinical centers have measured viral load using either the Roche Amplicor ultrasensitive test or the Bayer bDNA assay, but some have recently adopted the newer Roche PCR viral-load test, TaqMan HIV-1. In this report, investigators from the British Columbia Centre for Excellence in HIV/AIDS describe their clinical experience with the new assay.

During the first 3 months after the TaqMan assay was introduced at the center, 6.9% of patients were found to have detectable viral loads after having had undetectable viral loads on the Amplicor assay at least three times in the preceding 15 months. By compariso…