The Efficacy of Tuberculosis Diagnosis and Drug Sensitivity Using Line Probe Assay and Standard methods in the Area under the Responsibility of the Office of Disease Prevention and Control 9, Nakhon Ratchasima

Abstract

Mycobacterium tuberculosis (MTB) poses a significant global health challenge in Thailand, particularly Multidrug-resistant tuberculosis (MDR-TB), resistant to rifampicin and isoniazid drugs. The diagnosis of MDR-TB traditionally relies on conventional culture and drug susceptibility testing (DST) using solid and liquid mediums, which can result in a prolonged turnaround time for result interpretation. To address this issue, the Office of Disease Prevention and Control 9, Nakhon Ratchasima, introduced Line Probe Assay (LPA) for molecular diagnosis of MDR-TB, aiming to expedite the diagnostic process. A retrospective descriptive study was conducted, analyzing secondary data collected routinely from the laboratory for individual patients diagnosed with TB between October 1, 2019, and September 30, 2020. A total of 335 specimens were included in the analysis. The study aimed to compare the efficacy of LPA (Genotype MTBDRplus VER 2.0) and DST in detecting INH and RIF-resistant tuberculosis. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of LPA were analyzed using standard DST as a golden reference. Results from the standard DST revealed that 25 isolates (7.5%) were MDR-TB, while 25 (7.5%) were INH-resistant, and 285 (85%) were susceptible to both INH and RIF. The efficiency of LPA by Genotype MTBDRplus VER 2.0 for detecting INH-resistant, RIF-resistant, and MDR-TB showed 90%, 91.7%, and 84% sensitivity, with specificity rates of 98.9%, 99.3%, and 100%, respectively. The overall accuracy was 97.6%, 98.8%, and 98.8%, with PPV and NPV values indicating high diagnostic reliability. In conclusion, LPA demonstrated high sensitivity, specificity, and accuracy in detecting drug-resistant tuberculosis. This molecular method holds promise for facilitating early and appropriate treatment for tuberculosis patients and preventing the community spread of MDR-TB.