Diagnostic Accuracy of Saliva for Molecular Detection of SARS CoV-2 for Diagnosis of COVID 19: a Comparative Study

Abstract

Throat swab, Nasal swab, Nasopharyngeal swab, Bronchoalveolar lavage fluid and Endotracheal aspirate are the recommended samples by Indian Council of Medical Research for molecular detection of SARS-CoV-2. Saliva specimen is less invasive, can be collected by oneself thus minimizing the risk to the healthcare workers to SARS-CoV-2 exposure. The present study was aimed to evaluate better possible sample collection method among nasal swab, Throat swab and saliva samples of patients for precise COVID-19 diagnosis. A prospective study conducted for diagnosis of COVID-19 samples. three type of samples Nasal and Throat swab and saliva collected for COVID-19 diagnosis. If sample was found positive then Throat and nasal swabs were collected every alternative day while saliva collected every day for COVID-19 diagnosis by RT-PCR. 172 samples of patients were found to be positive for COVID-19. 103 (59.88 %) males and 69 (40.11 %) were females. Throat and Nasal swabs were collected every alternative day. Nasal swab was the best method of sample collection and gave most effective results followed by throat swab in comparison with the saliva sample. Saliva specimen showed positivity only for upto 3 days, while TS and NS specimens showed higher positivity in comparison with saliva specimens for upto 7 days. Further research on usefulness of less invasive saliva specimen is required.