Hueda-Zavaleta Miguel, Copaja-Corzo Cesar, Benites-Zapata Vicente A, Cardenas-Rueda Pedro, Maguiña Jorge L, Rodríguez-Morales Alfonso J
Faculty of Health Sciences, Universidad Privada de Tacna, Tacna, 23003, Peru.
Hospital III Daniel Alcides Carrión EsSalud, Tacna, 23000, Peru.
Ann Clin Microbiol Antimicrob. 2022 Mar 14;21(1):11. doi: 10.1186/s12941-022-00501-x.
The rapid spread of SARS-CoV-2 has created a shortage of supplies of reagents for its detection throughout the world, especially in Latin America. The pooling of samples consists of combining individual patient samples in a block and analyzing the group as a particular sample. This strategy has been shown to reduce the burden of laboratory material and logistical resources by up to 80%. Therefore, we aimed to evaluate the diagnostic performance of the pool of samples analyzed by RT-PCR to detect SARS-CoV-2.
A cross-sectional study of diagnostic tests was carried out. We individually evaluated 420 samples, and 42 clusters were formed, each one with ten samples. These clusters could contain 0, 1 or 2 positive samples to simulate a positivity of 0, 10 and 20%, respectively. RT-PCR analyzed the groups for the detection of SARS-CoV-2. The area under the ROC curve (AUC), the Youden index, the global and subgroup sensitivity and specificity were calculated according to their Ct values that were classified as high (H: ≤ 25), moderate (M: 26-30) and low (L: 31-35) concentration of viral RNA.
From a total of 42 pools, 41 (97.6%) obtained the same result as the samples they contained (positive or negative). The AUC for pooling, Youden index, sensitivity, and specificity were 0.98 (95% CI, 0.95-1); 0.97 (95% CI, 0.90-1.03); 96.67% (95% CI; 88.58-100%) and 100% (95% CI; 95.83-100%) respectively. In the stratified analysis of the pools containing samples with Ct ≤ 25, the sensitivity was 100% (95% CI; 90-100%), while with the pools containing samples with Ct ≥ 31, the sensitivity was 80% (95% CI, 34.94-100%). Finally, a higher median was observed in the Ct of the clusters, with respect to the individual samples (p < 0.001).
The strategy of pooling nasopharyngeal swab samples for analysis by SARS-CoV-2 RT-PCR showed high diagnostic performance.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的迅速传播导致全球范围内其检测试剂供应短缺，尤其是在拉丁美洲。样本混合是指将个体患者样本分组合并，并将该组作为一个特定样本进行分析。这一策略已被证明可将实验室材料和后勤资源负担减轻多达80%。因此，我们旨在评估通过逆转录聚合酶链反应（RT-PCR）分析样本混合以检测SARS-CoV-2的诊断性能。
开展了一项诊断试验的横断面研究。我们对420个样本进行了单独评估，并形成了42个组群，每组10个样本。这些组群可能包含0、1或2个阳性样本，分别模拟0%、10%和20%的阳性率。RT-PCR对这些组群进行分析以检测SARS-CoV-2。根据样本的Ct值计算曲线下面积（AUC）、约登指数、总体及亚组的敏感性和特异性，Ct值被分类为高（H：≤25）、中（M：26 - 30）和低（L：31 - 35）浓度的病毒RNA。
在总共42个混合样本中，41个（97.6%）与其中所含样本得出相同结果（阳性或阴性）。混合样本的AUC、约登指数、敏感性和特异性分别为0.98（95%置信区间，0.95 - 1）；0.97（95%置信区间，0.90 - 1.03）；96.67%（95%置信区间；88.58 - 100%）和100%（95%置信区间；95.83 - 100%）。在对Ct≤25的样本组成的混合样本进行分层分析时，敏感性为100%（95%置信区间；90 - 100%），而对于Ct≥31的样本组成的混合样本，敏感性为80%（95%置信区间，34.94 - 100%）。最后，观察到组群的Ct中位数相对于个体样本更高（p < 0.001）。
采用SARS-CoV-2 RT-PCR分析鼻咽拭子样本混合策略显示出较高的诊断性能。
