The Performance of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) Virus Using the Colorimetric Reverse-Transcription Loop Mediated Isothermal Amplification (RT-LAMP) Method in Saliva Specimens of Suspected COVID-19 Patients

Abstract

Dewi Kartika Turbawaty, Andy Sudjadi, Leni Lismayanti, Tiene Rostini, Verina Logito Department of Clinical Pathology, Faculty of Medicine Padjadjaran University/ Dr. Hasan Sadikin General Hospital, Bandung, West Java, IndonesiaCorrespondence: Dewi Kartika Turbawaty, Email [email protected]: Corona Virus Disease-19 (COVID-19) is a disease caused by Severe-Acute-Respiratory-Syndrome-Coronavirus-2 (SARS-CoV-2). The most reliable and widely accepted method for diagnosing this infection, despite facing various challenges, is the Reverse Transcription Polymerase Chain Reaction (RT-PCR) method, which utilizes nasopharyngeal swab sample. Reverse-transcription loop mediated isothermal amplification (RT-LAMP) is a simpler nucleic acid amplification method compared to the RT-PCR method. This method has several advantages, including: of amplification at constant temperature, faster results, and potentially greater examination capacity.Purpose: This study aimed to compare the validity of the RT-LAMP method using saliva specimens with that of the RT-PCR method using nasopharyngeal smears.Methods: This was an analytical observational study with a cross-sectional design. The participants were inpatients in the COVID-19 special isolation building of Hasan Sadikin General Hospital, Indonesia with a probable (clinical symptoms of covid, but not confirm NAAT examination) or confirmed diagnosis of COVID-19 from September 2021 to February 2022. The inclusion criteria are COVID-19 patients with symptoms, adult subjects, and composite mentions. Patients who were unable to secrete saliva were also excluded.Results: In total, 118 specimens were collected. The validity test results of the saliva specimens using the RT-LAMP method showed sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), of 65.5%, 100%, 100%, and 75%, respectively. The results increased in subjects treated between 3 and 7 days after symptom onset ie 73.2%, 100%, 100%, and 82.3%, respectively.Conclusion: The very strong specificity accompanied by good sensitivity and NPV in the group of subjects treated 3– 7 days after the onset of symptoms indicates that the RT-LAMP method using saliva specimens can be an efficient and reliable alternative tool in detecting the SARS-CoV-2 virus.Keywords: COVID-19, SARS-CoV-2, RT-LAMP, RT-PCR, saliva

Keywords

• covid-19
• sars-cov-2
• rt-lamp
• rt-pcr
• saliva