Abstract:

Objective To explore the clinical value of GeneXpert MTB/RIF detection in the diagnosis of pulmonary tuberculosis and its drug resistance.Methods A total of 981 patients admitted to the Department of Tuberculosis of Suzhou Fifth People’s Hospital from August 2017 to November 2018 were selected. The results of acid fast staining microscopic examination(Abbreviated as “smear method”),GeneXpert MTB/RIF(Abbreviated as “GeneXpert”), BACTEC MGIT 960 tuberculosis culture(Abbreviated as“MGIT 960”) and proportional drug sensitivity test of sputum(Abbreviated as“drug sensitive test”)and alveolar lavage fluid (Bronchoalveolar lavage fluid, BALF) were analyzed to evaluate the diagnostic efficacy of the three methods.Results According to the standard of clinical diagnosis, the sensitivity of sputum smear, GeneXpert and BACTEC MGIT 960 in the diagnosis of pulmonary tuberculosis was 32.02% (276/862),53.02% (457/862) and 53.25% (459/862),respectively.The sensitivity of the three methods was 31.32% (270/862), 72.97% (629/862) and 69.37% (598/862). Among the 527 patients with pulmonary tuberculosis who were both positive for BACTEC MGIT 960 and GeneXpert, 28 cases were RFP resistant by proportional drug sensitivity test,26 cases were drug resistant by GeneXpert, and the other 2 cases were sensitive. The results of proportional assay showed that rifampicin was sensitive in 499 cases, GeneXpert was sensitive in 497 cases, and the remaining 2 cases suggested drug resistance. The Kappa showed that those has good consistency (K=0.612, P<0.001). Take the solid proportional drug sensitivity test as standard, the sensitivity and specificity of GeneXpert in detecting RFP resistance were 92.86% (26/28) and 99.60% (497/499).Conclusion GeneXpert has high sensitivity and specificity. At the same time, the detection of RFP, resistance has a good application prospect in the early diagnosis and drug resistance detection of pulmonary tuberculosis. It is also found that the spiritual sensitivity of BALF GeneXpert is significantly higher than that of sputum samples, so electronic tracheoscopy should be performed in the early stage.

Key words: Tuberculosis, pulmonary, Diagnostic techniques and procedures, Microbial sensitivity tests, Rifampin, Nucleic acid amplification techniques, Evaluation studies