Evaluation of different respiratory samples and saliva for the detection of SARS-CoV-2 RNA

Objective: We aimed to analyse the positivity rate and cycle threshold values indicating viral loads for SARS CoV-2 among different respiratory specimens. Additionally, we evaluated diagnostic efficacy of saliva samples. Patients Methods: included combined oropharyngeal nasopharyngeal swab (cONS), sputum, tracheal aspirate (TA) specimens patients. Unpreserved samples were collected prospectively from hospitalized patients within 72 hours admission. RNA was extracted by using Bio-Speedy nucleic acid buffer than RT-PCR performed with Bio- Speedy COVID-19 qPCR detection kit. Results: Retrospective evaluation revealed in 19.66% cONS (n: 5819), 30.77% sputum 39), 29.41% TA 34) 4812 In majority (86.72%) samples, first sample positive. Consecutive sputum/TA investigated 52 whom 11 positive either these Saliva detected 60% 20) 30% negative 12) Conclusion: Although, show greatest guidance, repeated sampling multiple sites tract increases possibility diagnosis. might be considered as an alternative specimen.