Abstract:

Objective To analyze the application value of GeneXpert MTB/RIF in detecting sputum specimens of patients with pulmonary tuberculosis (PTB). Methods 1355 untreated patients were continuously selected from the outpatient clinic of Heilongjiang Tuberculosis Control and Prevention Center from August 2015 to January 2017, including 636 active PTB patients and 719 non-active PTB patients. The sputum samples of the patients were collected for sputum smear test, sputum culture test, proportional drug susceptibility test (DST), and GeneXpert MTB/RIF test. The detection performance of GeneXpert was analyzed. Results Sputum smear test was positive in 173 cases and negative in 1182 cases. Sputum culture was positive in 317 cases and negative in 1038 cases. GeneXpert detection was positive in 386 cases and negative in 969 cases. Taking the smear test as standard, the sensitivity and specificity of GeneXpert were 98.3% (170/173) and 81.7% (966/1182), respectively. Taking the culture test as standard, the sensitivity and specificity of GeneXpert were 93.4% (296/317) and 91.3% (948/1038), respectively. Taking the clinical diagnosis as standard, the sensitivity and specificity of GeneXpert were 58.0% (369/636) and 97.6% (702/719), respectively. Taking the DST as standard, the sensitivity and specificity of GeneXpert were 85.5% (47/55) and 98.3% (237/241), respectively, regarding the detection of rifampicin resistance. Conclusion With high sensitivity, high specificity, short detection time, and low requirements on laboratory biosafety and technical level of personnel, GeneXpert is suitable for the application in the grassroots laboratory.

Key words: Tuberculosis, pulmonary, Polymerase-chain reaction, Sputum, Evaluation research