BACKGROUND: An optimal clinical specimen for an accurate detection of SARS-CoV-2 by minimizing the usage of consumables and reduce hazard exposure to healthcare workers is a dire priority . The diagnostic performance of SARS-CoV-2 detection between healthcare worker-collected nasopharyngeal and oropharyngeal (NP+OP) swabs and patient performed self-collected random saliva was assessed .
METHODS: Paired NP+OP swabs and random saliva were collected and processed within 48 hours of specimen collection from two cohort study which recruited 562 asymptomatic adult candidates. Real time reverse transcriptase polymerase chain reaction (qRT-PCR) targeting Open reading frame 1a (ORF1a) and nucleocapsid (N) genes was performed and the results were compared .
RESULTS: Overall , 65 of 562 (28.1 %) candidates tested positive for COVID-19 based on random saliva, NP+OP swabs or both testing techniques . The detection rate of SARS-CoV-2 was higher in random saliva compared to NP+OP testing (92.3% ; 60/65 versus 73.8% ; 48/65; p <0.05). The estimated sensitivity and specificity of random saliva were higher than NP+OP swabs (95.0; 99.9 vs 72.2; 99.4). The Ct-values of ORF1a and N genes were significantly lower in random saliva compared to NP+OP swabs specimens .
CONCLUSIONS: Our findings demonstrate that random saliva is an alternative diagnostic specimen for detection of SARS-CoV-2 . Self-collected random oropharyngeal saliva is a valuable specimen which provides accurate SARS-CoV-2 surveillance testing of a community . This article is protected by copyright . All rights reserved.