Services on Demand
Journal
Article
Indicators
- Cited by SciELO
- Access statistics
Related links
- Cited by Google
- Similars in SciELO
- Similars in Google
Share
Biomédica
Print version ISSN 0120-4157On-line version ISSN 2590-7379
Abstract
HURTADO, Leidy et al. Clinical validation of the isothermal RT-LAMP test for rapid diagnosis of SARS-CoV-2. Biomed. [online]. 2022, vol.42, suppl.2, pp.59-72. Epub Oct 31, 2022. ISSN 0120-4157. https://doi.org/10.7705/biomedica.6523.
Introduction:
Since the first report in Wuhan (China) in 2019, the SARS-CoV-2 virus has spread throughout the world, with a significant impact in public health. To contain its transmission, the WHO has encouraged the development of rapid, simple, sensitive and specific tests that complement qRT-PCR, as the gold standard. RT-LAMP has shown to be a good alternative to detect SARS-CoV-2 in different fluid samples.
Objective:
To validate the colorimetric RT-LAMP technique using two sets of primers targeting N gene of SARS-CoV-2 in 117 nasopharyngeal swab samples previously confirmed by RT-qPCR, using the Charité/Berlin protocol.
Material and methods:
A total of 153 nasopharyngeal swab samples from individuals with suspected COVID-19 were subjected to qRT-PCR and RT-LAMP using a commercial colorimetric kit (NEB, Germany). RT-LAMP was performed using both extracted RNA samples and raw samples without prior RNA extraction, and the result was assessed by a simple color change in the reaction.
Results:
Sensitivity and specificity for the previously reported RT-LAMP primers (Broughton set) targeting N gene of SARS-CoV-2 were 0.97 (0.85-1.00) and 0.81 (0.65-0.92) respectively, with CI95%. The Lalli primers targeting another region of the N gene used showed a sensitivity value of 0.96 (0.78-1.00) and a specificity of 0.77 (0.55-0.92). Without RNA extraction we found a sensitivity value of 0.95 (0.74, 1.00) and a specificity of 0.88 (0.64, 0.99). A sensitivity value of 0.95 (0.74-1.00) and a specificity 0.88 (0.64-0.99) were found without prior RNA extraction.
Conclusion:
Taking together, the results showed that RT-LAMP technique could be considered as a rapid diagnostic test, easy to perform, free of sophisticated equipment, sensitive and specific to diagnose SARS-CoV-2 in nasopharyngeal swabs with and without prior RNA extraction, allowing its implementation in places with scarce resources.
Keywords : COVID-19/diagnosis; molecular diagnostic techniques; sensitivity and specificity; point-of-care testing.