Shanghai Institute of Infectious Disease and Biosecurity, Key Laboratory of Medical Molecular Virology (MOE/ NHC/CAMS), School of Basic Medical Science, Fudan University, Shanghai, China.
Wusheng County Center for Disease Control and Prevention, Guang'an, China.
Tuberculosis (Edinb). 2024 Dec;149:102575. doi: 10.1016/j.tube.2024.102575. Epub 2024 Nov 8.
The sensitivity of Xpert MTB/RIF (Xpert) pooled testing is limited for diagnosing patients with paucibacillary tuberculosis (TB). We assessed whether pooled testing with Xpert MTB/RIF Ultra (Ultra) can be a sensitive and effective approach for mass TB screening. Conserved, frozen sputum samples, previously confirmed as positive or negative for Mycobacterium tuberculosis by individual Xpert assays, were mixed in pools of 4, 8, and 16 and then tested using Ultra. Each pool contained a single positive sample with varying mycobacterial loads. We then simulated TB screening at prevalence ranges of 0.2-1.0 % and calculated the cartridges required per case detected at different pool sizes. The overall sensitivity of Ultra pooled testing was high (88.9 %, 75.9-96.3). Sensitivity was greater in pools in which the positive sample had a high mycobacterial load compared to those with scant bacilli. As prevalence increased, the optimal pool size and benefits of pooled testing declined, but a pool size of 8 resulted in at least 80 % cartridge savings with the highest simulated prevalence. Sputum pooling using Ultra could be a sensitive and effective strategy for TB screening. However, broad TB screening in communities with limited resources will require new, lower-cost, high-throughput screening tools, perhaps based on non-sputum specimens.
Xpert MTB/RIF（Xpert）混合检测诊断菌量少的结核病（TB）患者的灵敏度有限。我们评估了 Xpert MTB/RIF Ultra（Ultra）混合检测是否可以作为一种用于大规模 TB 筛查的敏感且有效的方法。将先前通过单个 Xpert 检测法确认为结核分枝杆菌阳性或阴性的冷冻痰液样本保存在 4、8 和 16 个混合池里，然后用 Ultra 进行检测。每个混合池里有一个含有不同分枝杆菌载量的阳性样本。然后我们模拟了在 0.2-1.0%流行率范围内的 TB 筛查，并计算了在不同混合池大小下每检出一个病例所需的检测卡数。Ultra 混合检测的总体灵敏度很高（88.9%，75.9-96.3）。阳性样本中分枝杆菌载量高的混合池比载量低的混合池的灵敏度更高。随着流行率的增加，最优的混合池大小和混合检测的优势下降，但在最高模拟流行率下，混合池大小为 8 可节省至少 80%的检测卡。使用 Ultra 进行痰液混合检测可能是一种用于 TB 筛查的敏感且有效的策略。然而，在资源有限的社区中进行广泛的 TB 筛查将需要新的、成本更低、高通量的筛查工具，也许是基于非痰液样本的工具。
