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.

INTRODUCTION

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.