The Diagnostic Value Of GeneXpert MTB/RIF In Children With Tuberculosis

Objective : To evaluate the value of rifampin resistant real-time fluorescent quantitative nucleic acid amplification(xpert MTB / RIF)in the diagnosis of tuberculosis in children.Methods : A retrospective study of 265 children with suspected tuberculosis hospitalized in the children’s Hospital Affiliated to Chongqing Medical University from January 2018 to may 2019 was conducted to compare the sensitivity and specificity of Xpert MTB / RIF,smear test,T-SPOT test,TST and Mycobacterium tuberculosis culture for detection of Mycobacterium tuberculosis in children’s tuberculosis samples and to analyze the diagnostic value of xpert MTB / RIF method.Results:Among 265 children with suspected tuberculosis,153 were diagnosed with tuberculosis and 112 were non-tuberculosis.The sensitivity of MTB / RIF,smear,T-SPOT,TST and Mycobacterium tuberculosis culture was 32.0%,29.8%,86.2%,69.6% and 25.4%(P < 0.05),the difference was statistically significant;the specificity was 100%,100%,96.9%,91.9% and 100%;the positive predictive value was 100%,100%,97.8%,93.1% and 97.2%;the negative predictive value was 51.9%,48.0%,81.7%,65.7%,35.2%。 The sensitivity of xpert MTB / RIF was 25.3%,21.7%,21.2%,32.1%,32%(P = 0.800)in sputum,gastric fluid,cerebrospinal fluid,lavage fluid and other specimens(pus,urine,stool,pleural fluid,ascites,etc.),and the sensitivity of smear in sputum,gastric fluid,cerebrospinal fluid,lavage fluid and other specimens was 15.9%,12.9%,10.2%,15.4%,33.3%(P < 0.05).The sensitivity of xpert MTB /RIF,smear,T-SPOT,TST and Mycobacterium tuberculosis culture were34.0%,23.9%,82.6%,69.0% and 37.8% respectively in the 5-year-old group and younger group,and 31.1%,32.4%,87.7%,69.9% and 19.4% in the 5-year-old group and older group.For smear positive and culture positive children,the sensitivity of xpert MTB / RIF was 48.9% and 62.9%respectively,which was significantly higher than that of clinical diagnosis(32%).Conclusion : T-SPOT has high sensitivity and specificity in the diagnosis of tuberculosis.Xpert MTB / RIF,smear examination and Mycobacterium tuberculosis culture have high specificity in the detection of tuberculosis,but the sensitivity is significantly lower than T-SPOT and TST.The detection method of xpert MTB / RIF has no obvious advantage in the diagnosis of tuberculosis in children.