Performance of Xpert/MTB/RIF assay for childhood pulmonary tuberculosis among HIV negative children with real world evidence in China

Abstract Background Rapid and accurate notification of childhood pulmonary tuberculosis (PTB) is a worldwide challenge. Although the Xpert MTB/RIF assay (Xpert) has been endorsed as the initial test for suspected PTB in many countries, limited studies have reported the performance of Xpert in childhood PTB. The aim of this study is to evaluate the real-world performance of Xpert for the detection of childhood PTB among HIV negative children in China. Methods We consecutively extracted the data of all patients ≤14 years with pulmonary disease through the electronic medical record (EMR) systems of Shanghai Public Health Clinical Center from January 2014 to December 2017. The clinical profile, the decision-making tests including AFB smear, solid/liquid culture, pathological examination and Xpert result were matched and assessed. The real diagnostic accuracy and the all-factors case notification rate for childhood PTB with the implementation of Xpert were evaluated. Results 519 HIV negative cases ≤14 years with pulmonary disease were extracted from the data base. Of these, 145 had matched results, there were 374 non-matched cases including 346 with incomplete or unavailable data and 28 with NTM, BCG or an unidentified strain. For matched data, the overall sensitivity and specificity of the Xpert assay were 66.7% (32/48, 95%CI 0.52–0.80) and 87.6% (85/97, 95%CI 0.87–0.98) respectively against the gold standard; 34.6% (44/127, 95%CI 26.6–43.7) and 100% against the composite clinical reference standard (CCRS). The all-factors case notification rate by Xpert was 29%. Conclusion Xpert/MTB RIF assay has acceptable sensitivity and excellent specificity for rapid diagnosis of children with pulmonary TB as well as for the detection of RIF resistance in China. However, implementation of Xpert for the initial diagnosis of childhood PTB is inadequate to meet the urgent requirement for rapid and accurate detection of childhood PTB.