1. Point-of-care testing for COVID-19: a simple two-step molecular diagnostic development and validation during the SARS-CoV-2 pandemic.
- Author
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Yoshikawa AAG, Cardoso SF, Eslabão LB, Pinheiro IC, Valverde P, Caminha G, Romero OB, Medeiros L, Rona LDP, and Pitaluga AN
- Subjects
- Humans, RNA, Viral analysis, RNA, Viral isolation & purification, COVID-19 Nucleic Acid Testing methods, Pandemics, Brazil, Nasopharynx virology, Reproducibility of Results, COVID-19 Testing methods, COVID-19 diagnosis, Point-of-Care Testing, SARS-CoV-2 genetics, SARS-CoV-2 isolation & purification, Molecular Diagnostic Techniques methods, Nucleic Acid Amplification Techniques methods, Sensitivity and Specificity, Saliva virology
- Abstract
Background: During the coronavirus disease 19 (COVID-19) pandemic, diagnostic testing of the general population proved challenging due to limitations of the gold-standard diagnostic procedure using reverse transcription real-time polymerase chain reaction (RT-qPCR) for large-scale testing on the centralised model, especially in low-resource areas., Objectives: To address this, a point-of-care (PoC) diagnostic protocol for COVID-19 was developed, providing fast, reliable, and affordable testing, particularly for low-mid develop areas., Methods: The PoC diagnostic process combines a simple paper-based RNA extraction method housed within a 3D-printed plastic device with a colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay. Nasopharyngeal/oropharyngeal swabs (NOS) and saliva samples were tested between 2020 and 2021, with the assistance of Santa Catarina's State Health Secretary, Brazil., Findings: The developed diagnostic protocol showed a limit of detection of 9,900 copies and an overall diagnostic specificity of 98% for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from 1,348 clinical analysed samples. The diagnostic sensitivity was 95% for NOS samples, 85% for early morning saliva, and 69% for indiscriminate saliva., Main Conclusions: In conclusion, the developed device successfully extracted SARS-CoV-2 viral RNA from swabs and saliva clinical samples. When combined with colorimetric RT-LAMP, it provides results within 45 min using minimal resources, thus delivering a diagnostic kit protocol that is applicable in large-scale sampling.
- Published
- 2024
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