GeneXpert MTB/RIF evaluated in diagnosis of pulmonary tuberculosis

ObjectiveTo evaluate GeneXpert MTB/RIF in diagnosis of pulmonary tuberculosis by comparing the lab results of diagnosed patients.

MethodsA total of 97 diagnosed pulmonary tuberculosis patients were enrolled from July 2017 to June 2018.Sputum smear microscopy (Ziehl-Neelsen stain), sputum culture (MGIT liquid culture) and Xpert MTB/RIF were conducted in all patients.Drug susceptibility test and strain identification by PNB were done for culture positive sputum samples.Consistency rate was calculated.

ResultsIn terms of M.tuberculosis detection, sensitivity and specificity of GeneXpert were 93.44% and 55.55%, respectively, compared with bacteriological examination (consistency rate 79.38%).Consistency rate of GeneXpert and PNB is 94.55%.In terms of RIF resistance test, sensitivity and specificity of GeneXpert were 66.67% and 98.08%, respectively, compared with phenotypic drug-susceptibility testing (consistency rate 96.36%).

ConclusionGeneXpert MTB/RIF can be utilized in combination with smear microscopy and liquid culture to diagnose more etiologically positive patients, and can spot RIF resistance patients early.But strain identification and drug susceptibility test are still needed for individualized therapy and optimal treatment outcome.