Table_1_A Novel Cross-Priming Amplification-Based Assay for Tuberculosis Diagnosis in Children Using Gastric Aspirate.DOCX

Low detection rates of Mycobacterium tuberculosis (MTB) by culture and smear microscopy prevent early diagnosis of tuberculosis (TB) in children. Therefore, developing rapid and accurate diagnostic techniques are critical to achieving the global aim of minimizing childhood TB. The present study was performed to evaluate the diagnostic effectiveness of the novel cross-priming amplification-based EasyNAT MTB complex assay (EasyNAT) in childhood TB. Five hundred and six children with suspected TB were enrolled from January 2018 to October 2021. Gastric aspirate (GA) samples were tested by bacterial culture, acid-fast bacillus microscopy, EasyNAT, Xpert MTB/RIF (Xpert), or Xpert MTB/RIF Ultra (Xpert Ultra). Among 239 children simultaneously tested by EasyNAT and Xpert methods, both assays showed similar sensitivities in total active TB cases [22.6% (31/137) vs. 26.3% (36/137), p = 0.441] and in bacteriologically confirmed TB cases [both 60.0% (9/15)]. The two assays presented similar specificities of 98.0% (100/102) and 99.0% (101/102), respectively (p = 1.000). Among 267 children who were simultaneously tested with EasyNAT and Xpert Ultra, Xpert Ultra demonstrated higher sensitivity than EasyNAT in total active TB cases [50.9% (89/175) vs. 30.3% (53/175), p < 0.001]. EasyNAT and Xpert Ultra yielded similar specificities, at 97.8% (90/92) and 100.0% (92/92), respectively (p = 0.155). These findings indicated that Xpert Ultra was superior to EasyNAT despite its higher cost and EasyNAT was not inferior to Xpert in the diagnosis of childhood TB using GA samples. EasyNAT may therefore be a suitable alternative diagnostic method for childhood TB based on its cost-effectiveness, speed, and accuracy.

传统培养法与涂片显微镜检查对结核分枝杆菌（Mycobacterium tuberculosis, MTB）的检出率偏低，阻碍了儿童结核病（tuberculosis, TB）的早期诊断。因此，开发快速精准的诊断技术，对实现全球降低儿童结核病负担的防控目标至关重要。本研究旨在评估新型基于交叉引物扩增（cross-priming amplification）的EasyNAT结核分枝杆菌复合群检测试剂盒（EasyNAT MTB complex assay，下称EasyNAT）在儿童结核病诊断中的诊断效能。
本研究于2018年1月至2021年10月期间纳入506例疑似结核病的儿童受试者。对其胃液抽吸物（Gastric aspirate, GA）样本分别采用细菌培养法、抗酸杆菌显微镜检查、EasyNAT、Xpert MTB/RIF（下称Xpert）以及Xpert MTB/RIF Ultra（下称Xpert Ultra）进行检测。
在同时接受EasyNAT与Xpert检测的239例儿童中，两种检测方法在全部活动性结核病病例中的敏感度相近[22.6%（31/137） vs. 26.3%（36/137），p=0.441]；在细菌学确诊的结核病病例中，二者敏感度亦完全一致[均为60.0%（9/15）]。两种检测方法的特异性分别为98.0%（100/102）与99.0%（101/102），差异无统计学意义（p=1.000）。
在同时接受EasyNAT与Xpert Ultra检测的267例儿童中，Xpert Ultra在全部活动性结核病病例中的敏感度显著高于EasyNAT[50.9%（89/175） vs. 30.3%（53/175），p<0.001]；二者特异性相近，分别为97.8%（90/92）与100.0%（92/92），差异无统计学意义（p=0.155）。
本研究结果显示，尽管Xpert Ultra成本更高，但其诊断效能优于EasyNAT；而采用胃液抽吸物样本开展儿童结核病诊断时，EasyNAT的表现并不劣于Xpert。鉴于EasyNAT具备成本效益佳、检测快速且精准的优势，其或可成为儿童结核病的理想替代诊断方法。