ABSTRACT
The delay between first-line antiretroviral therapy (ART) failure and initiation of second-line ART in resource-limited settings can be prolonged. Increasing evidence links delayed antiretroviral switch with increased risk for opportunistic infection (OI) and death, particularly in patients with advanced HIV at the time of first-line failure. As access to viral load (VL) monitoring widens beyond a few countries, mechanisms are needed to optimize the use of routine virologic monitoring and assure that first-line regimen failure results in prompt second-line switch. For patients with advanced HIV or OI at the time of first-line failure, a targeted fast track to second-line ART should be considered, involving a switch to second-line ART during a single visit. To derive the maximum benefit from both the current expansion of VL monitoring and the falling costs of second-line ART, clinics and healthcare workers should be given the tools and training to detect and switch patients with regimen failure before HIV disease progression.