Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Jun:107:195-200.
doi: 10.1016/j.ijid.2021.04.018. Epub 2021 Apr 20.

Diagnostic accuracy of LAMP versus PCR over the course of SARS-CoV-2 infection

Masato Inaba  1 , Yuki Higashimoto  2 , Yoko Toyama  3 , Tomoya Horiguchi  3 , Masaya Hibino  4 , Mitsunaga Iwata  4 , Kazuyoshi Imaizumi  3 , Yohei Doi  5
Affiliations

Diagnostic accuracy of LAMP versus PCR over the course of SARS-CoV-2 infection

Masato Inaba et al. Int J Infect Dis. 2021 Jun.

Abstract

Objective: Reverse transcription loop-mediated isothermal amplification (RT-LAMP) has been validated to diagnose several viral infections. However, its diagnostic accuracy in detecting SARS-CoV-2 in real-life clinical settings remains unclear. This study aimed to determine the diagnostic sensitivity and specificity of RT-LAMP compared to reverse transcription-quantitative polymerase chain reaction (RT-qPCR) over the disease course of COVID-19.

Methods: A total of 124 nasopharyngeal swab samples obtained from 24 COVID-19 patients were tested by RT-LAMP and RT-qPCR. Sensitivities and specificities of RT-LAMP compared with RT-qPCR were analyzed as a function of time from onset.

Results: Up to the 9th day after onset, the RT-LAMP had a positivity of 92.8%, and the sensitivity and specificity compared with RT-qPCR was 100%. However, after the 10th day after onset, the positivity of RT-LAMP decreased to less than 25%, and the concordance of positivity between the two methods was below 60%. The limit of detection of RT-LAMP was 6.7 copies/reaction.

Conclusions: Until the 9th day after the onset of symptoms, RT-LAMP had the same diagnostic accuracy as RT-qPCR. These findings suggest that RT-LAMP can be used as a diagnostic tool for COVID-19 as an alternative to RT-qPCR in the acute symptomatic phase of COVID-19.

Keywords: COVID-19; RT-LAMP; RT-qPCR; Sensitivity; Specificity.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Genomic copy numbers of SARS-CoV-2 RNA determined by RT-qPCR in Groups 1–4. The box indicates the 25th and 75th percentiles. The thin line within the box marks the median. * Statistical significance (P < 0.05).
Figure 2
Figure 2
Ultraviolet light detection at the end of the assay. Light gray indicates a positive reaction (+), and dark gray indicates a negative reaction (−).
Figure 3
Figure 3
Positivity rates of the RT-LAMP and RT-qPCR in each group of samples collected from patients with a confirmed diagnosis of COVID-19. Black bar, RT-qPCR; gray bar, LAMP methods. * Statistical significance (P < 0.05).
Figure 4
Figure 4
SARS-CoV-2 viral load of positive samples tested with RT-qPCR.
Figure 5
Figure 5
Positivity rate of RT-LAMP for each genomic copy number of SARS-CoV-2 RNA determined by RT-qPCR. * Statistical significance (P < 0.05).
Figure 6
Figure 6
SARS-CoV-2 viral load of positive samples tested with RT-qPCR for positive and negative RT-LAMP test results. * Statistical significance (P < 0.05).
See this image and copyright information in PMC

References

    1. Altawalah H., AlHuraish F., Alkandari W.A., Ezzikouri S. Saliva specimens for detection of severe acute respiratory syndrome coronavirus 2 in Kuwait: a cross-sectional study. J Clin Virol. 2020;132 - PMC - PubMed
    1. Augustine R., Hasan A., Das S., Ahmed R., Mori Y., Notomi T., et al. Loop-mediated isothermal amplification (LAMP): a rapid, sensitive, specific, and cost-effective point-of-care test for coronaviruses in the context of COVID-19 pandemic. Biology (Basel) 2020;9(8) - PMC - PubMed
    1. Beigel J.H., Tomashek K.M., Dodd L.E., Mehta A.K., Zingman B.S., Kalil A.C., et al. Remdesivir for the treatment of Covid-19 - final report. N Engl J Med. 2020;383(19):1813–1826. - PMC - PubMed
    1. Bwire G.M., Majigo M.V., Njiro B.J., Mawazo A. Detection profile of SARS-CoV-2 using RT-PCR in different types of clinical specimens: a systematic review and meta-analysis. J Med Virol. 2021;93(February (2)):719–725. - PMC - PubMed
    1. Chow F.W., Chan T.T., Tam A.R., Zhao S., Yao W., Fung J., et al. A rapid, simple, inexpensive, and mobile colorimetric assay COVID-19-LAMP for mass on-site screening of COVID-19. Int J Mol Sci. 2020;21(15) - PMC - PubMed

Supplementary concepts