Rapid diagnosis of drug resistant tuberculosis: current perspectives and challenges

Tuberculosis (TB) caused by Mycobacterium tuberculosis complex remains one of the major public health problems, especially in developing countries. The emergence of drug resistant tuberculosis (both multidrug resistant and extensively drug resistant tuberculosis) is widely considered a serious threat to global TB control. Rapid diagnosis of drug resistant tuberculosis is one of the cornerstones for global TB control as it allows early epidemiological and therapeutic interventions. The present article provides an overview of the various diagnostic options available for drug resistant tuberculosis, including rapid conventional tools and newer molecular methods. Newly developed rapid phenotypic tests include automated liquid based culture and susceptibility tests, thin layer agar cultures, TK medium, microscopic-observation drug susceptibility assay and phage-based assay. Among newly developed molecular methods, real-time polymerase chain reaction (RT-PCR) and line probe assays (LPAs) have been commercialised and widely used in clinical laboratories. To effectively address the threats of drug resistant tuberculosis, global initiatives are required to scale-up culture and drug susceptibility testing capacities. In parallel efforts are needed to expand the use of novel and emerging molecular technologies for rapid diagnosis of drug resistance.