Abstract：
OBJECTIVE: To comprehensively investigate the diagnostic performance of routinely used assays in MPXV testing, the National Center of Clinical Laboratories in China conducted a nationwide external quality assessment (EQA) scheme and an evaluated nine assays used by ≥ 5 laboratories in the EQA.
METHODS: MPXV virus-like particles with 2700, 900 and 300 copies/mL were distributed to 195 EQA laboratories. For extended analysis, triple-diluted samples from 9000 to 4.12 copies/mL were repeated 20 times using the assays employed by ≥ 5 laboratories. The diagnostic performance was assessed by analyzing EQA data and calculating the limits of detection (LODs).
RESULTS: The performance was competent in 87.69% (171/195) of the participants and 87.94% (175/199) of the datasets. The positive percentage agreements (PPAs) were greater than 99% for samples at 2700 and 900 copies/mL, and 95.60% (761/796) for samples at 300 copies/mL. The calculated LODs for the two clades ranged from 228.44 to 924.31 copies/mL and were greater than the LODs specified by the respective kits. EasyDiagnosis had the lowest calculated LODs and showed superior performance in EQA, whereas BioGerm and Sansure, with higher calculated LODs, did not perform well in EQA.
CONCLUSIONS: This study provides valuable information from the EQA data and evaluation of the diagnostic performance of MPXV detection assays. It also provided insights into reagent optimization and enabled prompt public health interventions for the outbreak.
METHODS: MPXV virus-like particles with 2700, 900 and 300 copies/mL were distributed to 195 EQA laboratories. For extended analysis, triple-diluted samples from 9000 to 4.12 copies/mL were repeated 20 times using the assays employed by ≥ 5 laboratories. The diagnostic performance was assessed by analyzing EQA data and calculating the limits of detection (LODs).
RESULTS: The performance was competent in 87.69% (171/195) of the participants and 87.94% (175/199) of the datasets. The positive percentage agreements (PPAs) were greater than 99% for samples at 2700 and 900 copies/mL, and 95.60% (761/796) for samples at 300 copies/mL. The calculated LODs for the two clades ranged from 228.44 to 924.31 copies/mL and were greater than the LODs specified by the respective kits. EasyDiagnosis had the lowest calculated LODs and showed superior performance in EQA, whereas BioGerm and Sansure, with higher calculated LODs, did not perform well in EQA.
CONCLUSIONS: This study provides valuable information from the EQA data and evaluation of the diagnostic performance of MPXV detection assays. It also provided insights into reagent optimization and enabled prompt public health interventions for the outbreak.
摘要：
目的：为了全面调查MPXV检测中常规使用的检测方法的诊断性能，中国国家临床实验室中心开展了一项全国性的外部质量评估(EQA)方案,并评估了EQA中≥5个实验室使用的9种检测方法.
方法：将具有2700、900和300拷贝/mL的MPXV病毒样颗粒分配给195个EQA实验室。对于扩展分析，使用≥5个实验室采用的分析方法,将9000~4.12拷贝/mL的三倍稀释样品重复20次.通过分析EQA数据并计算检测限（LOD）来评估诊断性能。
结果：在87.69％（171/195）的参与者和87.94％（175/199）的数据集中，表现良好。2700和900拷贝/mL样品的阳性百分比协议（PPAs）大于99％，和95.60%(761/796)的样品在300拷贝/mL。两个进化枝的计算的LOD范围为228.44至924.31拷贝/mL,并且大于由相应试剂盒规定的LOD。EasyDiagnosis的计算LOD最低,且在EQA方面表现优异,而生物细菌和桑瑟，计算的LOD较高，在EQA中表现不佳。
结论：本研究从EQA数据和MPXV检测试验的诊断性能评估中提供了有价值的信息。它还提供了有关试剂优化的见解，并为爆发提供了及时的公共卫生干预措施。
方法：将具有2700、900和300拷贝/mL的MPXV病毒样颗粒分配给195个EQA实验室。对于扩展分析，使用≥5个实验室采用的分析方法,将9000~4.12拷贝/mL的三倍稀释样品重复20次.通过分析EQA数据并计算检测限（LOD）来评估诊断性能。
结果：在87.69％（171/195）的参与者和87.94％（175/199）的数据集中，表现良好。2700和900拷贝/mL样品的阳性百分比协议（PPAs）大于99％，和95.60%(761/796)的样品在300拷贝/mL。两个进化枝的计算的LOD范围为228.44至924.31拷贝/mL,并且大于由相应试剂盒规定的LOD。EasyDiagnosis的计算LOD最低,且在EQA方面表现优异,而生物细菌和桑瑟，计算的LOD较高，在EQA中表现不佳。
结论：本研究从EQA数据和MPXV检测试验的诊断性能评估中提供了有价值的信息。它还提供了有关试剂优化的见解，并为爆发提供了及时的公共卫生干预措施。
