Evaluation of Xpert MTB/RIF Ultra assay for the diagnosis of childhood tuberculosis: a multicenter accuracy study.

A multicenter study was performed to evaluate the value of testing gastric aspirate (GA) with Xpert MTB/RIF Ultra assay (Ultra) for childhood TB detection in China. Totally, 129 children with active tuberculosis (TB) and 173 children without TB were enrolled. The sensitivity of Ultra in bacteriologically confirmed TB and probable TB cases was 87.5% (42/48) and 44.4% (36/81), respectively. The specificity of Ultra was high (99.4%, 172/173). When Ultra, culture, and acid-fast bacilli outcomes were integrated as a composite reference standard, the percentage of children with definite TB increased from 37.2% (48/129) to 67.4% (87/129). The sensitivity of Ultra is 80.0% (40/50) in children aged <4 years, which is significantly higher than that in older children (48.1%, 38/79) (p < 0.001). The Ultra assay conducted using GA samples can provide faster results, allowing an early and accurate TB diagnosis, especially in younger children with difficulty producing sputum.