National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Nonthaburi, Thailand.
Mae Sot Hospital, Ministry of Public Health, Tak, Thailand.
J Infect Dev Ctries. 2024 Aug 31;18(8):1196-1203. doi: 10.3855/jidc.19442.
COVID-19, an emerging infectious disease caused by SARS-CoV-2, continues to be a global public health threat. The development of a colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) can extend the availability of simple, reliable molecular tests for the rapid detection of COVID-19.
The RT-LAMP assay was developed using a new primer set targeting a portion of SARS-CoV-2 orf8. The method was validated at 63 ºC for 60 minutes with naked-eye visualization of the color change. The clinical performance was compared to a real-time reverse transcription-polymerase chain reaction (rtRT-PCR) using 273 RNA samples extracted from nasopharyngeal swab specimens.
The developed RT-LAMP was specific to SARS-CoV-2 with a limit of detection at 15 RNA copies per reaction. The assay demonstrated diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 90.48% (95% CI: 86.36-93.68%), 87.00% (95% CI: 81.53-91.33%), 100% (95% CI: 95.07-100%), 100% (95% CI: not available), and 73.74% (95% CI: 66.22-80.07%), respectively, compared to the rtRT-PCR. The greatest sensitivity of 98.03% (95% CI: 94.34-99.59%) was demonstrated in samples with the cycle threshold (Ct) values < 30 cycles.
The RT-LAMP method in this study showed good performance. The assay can increase the scope of laboratory testing for rapidly detecting SARS-CoV-2 in Thailand. Due to a decrease in COVID-19 cases, its application is beneficial when commercial alternatives are unavailable.
COVID-19 是一种由 SARS-CoV-2 引起的新发传染病，仍然是全球公共卫生威胁。开发比色逆转录环介导等温扩增（RT-LAMP）可以扩展简单可靠的分子检测方法，用于快速检测 COVID-19。
该 RT-LAMP 检测方法使用针对 SARS-CoV-2 orf8 部分的新引物组开发。该方法在 63°C 下验证 60 分钟，通过肉眼观察颜色变化进行可视化。通过对 273 个从鼻咽拭子标本中提取的 RNA 样本进行实时逆转录聚合酶链反应（rtRT-PCR）比较了该方法的临床性能。
开发的 RT-LAMP 对 SARS-CoV-2 具有特异性，反应的检测限为 15 个 RNA 拷贝/反应。该检测方法的诊断准确性、敏感性、特异性、阳性预测值和阴性预测值分别为 90.48%（95%CI：86.36-93.68%）、87.00%（95%CI：81.53-91.33%）、100%（95%CI：95.07-100%）、100%（95%CI：不可用）和 73.74%（95%CI：66.22-80.07%），与 rtRT-PCR 相比。在 Ct 值<30 个循环的样本中，检测方法的敏感性最高，为 98.03%（95%CI：94.34-99.59%）。
本研究中的 RT-LAMP 方法表现出良好的性能。该检测方法可以扩大泰国范围内对 SARS-CoV-2 的实验室检测范围。由于 COVID-19 病例减少，在商业替代品不可用时，该方法的应用是有益的。
