TY - JOUR
T1 - Low saliva pH can yield false positives results in simple RT-LAMP-based SARS-CoV-2 diagnostic tests
AU - Uribe-Alvarez, Cristina
AU - Lam, Quynh
AU - Baldwin, Donald
AU - Chernoff, Jonathan
N1 - Publisher Copyright:
Copyright: © 2021 Uribe-Alvarez et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2021/5
Y1 - 2021/5
N2 - Diagnosis of any infectious disease is vital for opportune treatment and to prevent dissemination. RT-qPCR tests for detection of SARS-CoV-2, the causative agent for COVID-19, are ideal in a hospital environment. However, mass testing requires cheaper and simpler tests, especially in settings that lack sophisticated machinery. The most common current diagnostic method is based on nasopharyngeal sample collection, RNA extraction, and RT-qPCR for amplification and detection of viral nucleic acids. Here, we show that samples obtained from nasopharyngeal swabs in VTM and in saliva can be used with or without RNA purification in an isothermal loop-mediated amplification (LAMP)-based assay, with 60–93% sensitivity for SARS-CoV-2 detection as compared to standard RT-qPCR tests. A series of simple modifications to standard RT-LAMP published methods to stabilize pH fluctuations due to salivary acidity resulted in a significant improvement in reliability, opening new avenues for efficient, low-cost testing of COVID-19 infection.
AB - Diagnosis of any infectious disease is vital for opportune treatment and to prevent dissemination. RT-qPCR tests for detection of SARS-CoV-2, the causative agent for COVID-19, are ideal in a hospital environment. However, mass testing requires cheaper and simpler tests, especially in settings that lack sophisticated machinery. The most common current diagnostic method is based on nasopharyngeal sample collection, RNA extraction, and RT-qPCR for amplification and detection of viral nucleic acids. Here, we show that samples obtained from nasopharyngeal swabs in VTM and in saliva can be used with or without RNA purification in an isothermal loop-mediated amplification (LAMP)-based assay, with 60–93% sensitivity for SARS-CoV-2 detection as compared to standard RT-qPCR tests. A series of simple modifications to standard RT-LAMP published methods to stabilize pH fluctuations due to salivary acidity resulted in a significant improvement in reliability, opening new avenues for efficient, low-cost testing of COVID-19 infection.
KW - COVID-19/diagnosis
KW - False Positive Reactions
KW - Humans
KW - Hydrogen-Ion Concentration
KW - Limit of Detection
KW - Molecular Diagnostic Techniques/methods
KW - Nasopharynx/virology
KW - Nucleic Acid Amplification Techniques/methods
KW - RNA, Viral/analysis
KW - SARS-CoV-2/genetics
KW - Saliva/chemistry
KW - Sensitivity and Specificity
UR - http://www.scopus.com/inward/record.url?scp=85105252801&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0250202
DO - 10.1371/journal.pone.0250202
M3 - Article
C2 - 33951060
SN - 1932-6203
VL - 16
SP - e0250202
JO - PLoS ONE
JF - PLoS ONE
IS - 5 May
M1 - e0250202
ER -
