ABSTRACT
Objectives: To investigate the role of Xpert MTB/RIF assay for rapid diagnosis of osteoarticular tuberculosis.Methods: From February 2014 to November 2014,pus specimens of 49 osteoarticular tuberculosis patients and 32 nontuberculosis patients were detected by Xpert MTB/RIF system,and the sensitivity,specificity,positive predictive value,negative predictive value,agreement rate of Xpert MTB/RIF system were calculated,and clinical diagnosis was used as the reference standard.All the pus specimens were detected by acid-fast stain and fast culturing(BACTECT MGIT 960),to find the difference of sensitivity and specificity among Xpert MTB/RIF,acid-fast stain,and fast culturing.The role of Xpert MTB/RIF assay for rapid diagnosis of osteoarticular tuberculosis was evaluated through the two factors above.Results: It took 2.3±0.2h to detect each pus specimen by Xpert MTB/RIF.Among the 49 osteoarticular disease patients,46 were positive,3 were negative by Xpert MTB/RIF test.Among the 32 nontuberculosis patients,1 was positive,31 were negative by Xpert MTB/RIF test.The sensitivity,specificity,positive predictive value,negative predictive value,agreement rate was 93.87%,96.87%,97.87%,91.17%,95.06% respectively for Xpert MTB/RIF assay.Among the 46 specimens which were positive by Xpert MTB/RIF test,10 had rifampicin resistance mutation,with the rate of rifampicin resistance mutation as 21.73%.Among the 49 osteoarticular disease patients,8 were positive,41 were negative by acid-fast stain test,the sensitivity was 17.39%,and based on fast culturing test,11 were positive,38 were negative,the sensitivity was 23.91%.All pus specimens of 32 nontuberculosis patients were negative by acid-fast stain test and fast culturing test.As for the sensitivity,Xpert MTB/RIF was superior to acid-fast stain and fast cultureing (P＜0.05).While as for the specificity,there was no statistical difference among Xpert MTB/RIF,acid-fast stain,or fast culturing (P＞0.05).Conclusions: The role of Xpert MTB/RIF assay for rapid diagnosis of osteoarticular tuberculosis is perfect.It is of time saving,high sensitivity and high specificity,which is superior to the traditional methods.