Comparative of MDR-TB detection between Conventional DST and Line Probe Assay (LPA)

Abstract

Tuberculosis (TB) is one of the serious problems of the worldwide. Thailand is listed in the 30 high TB burden and high Multidrug resistance tuberculosis (MDR-TB) burden countries. The screening and rapid diagnosis of TB/MDR-TB are the important goal of Thailand that leading to the End TB strategy according World Health Organization (WHO).  For laboratory diagnosis of TB, culture and drug susceptibility test (DST) as gold standard it results still take a several weeks. The rapid molecular diagnosis tests e.g. Line Probe Assay (LPA) that has been recommended by the WHO to the reduced turnaround time of drug resistance tuberculosis detection. LPA was used for MDR-TB detection in many setting of Thailand. Thus, the aim of this study is comparative of MDR-TB detection rifampicin (RIF) resistance and isoniazid (INH) resistance between LPA (by using Genotype® MTBDRplus assay) and DST in the lower north of Thailand. The efficacy of the LPA by Genotype® MTBDRplus assay showed 80.0% of sensitivity and 97.9% of specificity for the detection of RIF resistance whereas sensitivity and specificity of INH resistance detection was found to be 81.3% and 100.0% respectively. The sensitivity of MDR-TB detection was found to be 64.7%. Moreover, the predominantly mutation of RIF resistance was found 33.3 % at MUT3 mutation of rpoB gene whereas the predominantly mutation of INH resistance was found 65.4% at MUT1 mutation of katG gene. This study demonstrated that LPA by using Genotype® MTBDRplus assay is a rapid and high efficacy method to detection of MDR-TB.