Detection of pulmonary tuberculosis in children using the Xpert MTB/RIF Ultra assay on sputum: a multicenter study

Abstract

Microbiological confirmation is rare in children with active tuberculosis; therefore, a more accurate test is needed to detect pulmonary tuberculosis in children. In this multicenter study, we evaluated the utility of the Xpert MTB/RIF Ultra (Ultra) on sputum, an assay recommended by the World Health Organization to test for childhood tuberculosis in high-burden settings. Children with symptoms suggestive of tuberculosis were enrolled at three hospitals in China and categorized as having active tuberculosis or nontuberculosis. The sensitivity and specificity of Ultra were 42.1% (48/114) and 99.0% (208/210), respectively. Using three MTB culture results as the reference, the sensitivity of Ultra in the subset of 38 children with culturepositive and 76 children with culture-negative was 68.4% (26/38) and 28.9% (22/76), respectively(p < 0.001). A single MTB culture combined with a single Ultra could detect 54 (54/114,47.4%) cases with active TB, while repeated MTB culture combined with a single Ultra detected 60 (60/114, 52.6%) cases with active TB(p = 0.427). Among 155 children (58 with TB and 97 with RTIs) simultaneously tested with the Ultra and Xpert MTB/RIF (Xpert), the sensitivity of the Xpert (24.1%, 14/58) was lower than that of the Ultra (41.4%, 24/58; p = 0.048). Eight children were found to have rifampin-resistant MTB strains. The Xpert MTB/RIF Ultra assay should be implemented to test for pulmonary tuberculosis in children to achieve higher confirmation rates.

Diagnostic value of tNGS vs Xpert MTB/RIF in childhood TB

“…In addition, one case was RIF- sensitive tested by Xpert but RIF-resistant by tNGS. As no phenotypic drug susceptibility testing was available, whether this result was from laboratory induced contamination or mixed infection need further verification [ 5 ]. Except for RIF, tNGS can simultaneously detect the resistance of other first line drugs due to its high sequencing depth.…”

“…However, it has been estimated that almost two-thirds of childhood TB have not been reported [ 2 ]. And the diagnosis of TB in children is challenging due to the paucibacillary nature, nonspecific symptoms and radiological features, resulted in the underestimation of TB burden in children [ [3] , [4] , [5] ]. Furthermore, the bacteriological confirmation by acid-fast bacilli (AFB) smear microscopy and mycobacterial culture has low sensitivity in children [ [6] , [7] , [8] ].…”

Yield & accuracy of Gastric Lavage in non-expectorating adults with Suspected Pulmonary Tuberculosis

“… 6 Likewise Sputum Induction showed satisfactory diagnostic results of PTB detection, but it required isolated room along with negative pressure which is also not available in all regions of developing countries. 7 …”