Disease of consumption to extensively drug resistance tuberculosis: Race of techniques to enhance diagnosis

Abstract

Tuberculosis is one of the most ancient infectious diseases known to mankind. Detection of the causative organism, Mycobacterium tuberculosis, has experienced a series of advances from the late 19th century through early 21st century. The hierarchy of diagnosis ranges from smear microscopy with traditional Ziehl–Neelsen staining to advanced light-emitting diode–fluorescence microscopy staining to both solid and liquid culture, and more recently, to genotypic methods like nucleic acid amplification. Each procedure has its own merits and drawbacks in terms of specificity, sensitivity, minimum detectible number of bacilli, and most crucially, turnover time. The latest diagnostic tools, like geneXpert and line probe assays, have gone a step further by detecting drug resistance. Both early and accurate diagnosis based on the drug susceptibility test implies precise and prompt initiation of treatment, thereby curtailing not only the agony of patient but also the burden tuberculosis places on the health system.