Saliva as an Alternative Specimen for Molecular COVID-19 Testing in Community Settings and Population-Based Screening

• Main Authors: Senok A, Alsuwaidi H, Atrah Y, Al Ayedi O, Al Zahid J, Han A, Al Marzooqi A, Al Heialy S, Altrabulsi B, AbdelWareth L, Idaghdour Y, Ali R, Loney T, Alsheikh-Ali A
• Format: Article
• Language: English
• Published: Dove Medical Press 2020-10-01
• Series: Infection and Drug Resistance
• Subjects: sars-cov-2; nasopharyngeal swab; molecular test; population-based screening; saliva.
• Online Access: https://www.dovepress.com/saliva-as-an-alternative-specimen-for-molecular-covid-19-testing-in-co-peer-reviewed-article-IDR

Abiola Senok,1,* Hanan Alsuwaidi,1,* Yusrah Atrah,2 Ola Al Ayedi,3 Janan Al Zahid,2 Aaron Han,1 Asma Al Marzooqi,3 Saba Al Heialy,1,4 Basel Altrabulsi,5 Laila AbdelWareth,5,6 Youssef Idaghdour,7 Raghib Ali,7 Tom Loney,1 Alawi Alsheikh-Ali1 1College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates; 2Molecular Department, Unilabs UAE, Dubai, United Arab Emirates; 3Al Khawaneej Health Center, Dubai Health Authority, Dubai, United Arab Emirates; 4Meakins-Christie Laboratories, Research Institute of the McGill University Health Center, Montreal, QC, Canada; 5National Reference Laboratory, Abu Dhabi, United Arab Emirates; 6Pathology and Laboratory Medicine Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, United Arab Emirates; 7Public Health Research Center, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates*These authors contributed equally to this workCorrespondence: Abiola SenokCollege of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Building 14, Dubai Healthcare City, Dubai 505055, United Arab EmiratesTel [phone]Email [e-mail]: With the easing of restriction measures, repeated community-based sampling for tracking new COVID-19 infections is anticipated for the next 6 to 12 months. A non-invasive, self-collected specimen like saliva will be useful for such public health surveillance. Investigations on the use of saliva for SARS-CoV-2 RT-PCR have largely been among COVID-19 in-pa\tients and symptomatic ambulatory patients with limited work in a community-based screening setting. This study was carried out to address this paucity of data and reported discrepancies in diagnostic accuracy for saliva samples.Patients and Methods: From 29th June to 14th July 2020, adults presenting for COVID-19 testing at a community-based screening facility in Dubai, United Arab Emirates were recruited. Clinical data, nasopharyngeal swab in universal transport media and drooling saliva in sterile containers were obtained. Reverse transcriptase PCR amplification of SARS-CoV-2 RdRp and N genes was used to detect the presence of the SARS-CoV-2 virus.Results: Of the 401 participants, 35 (8.7%) had viral detection in at least one specimen type and the majority (n=20/35; 57.1%) were asymptomatic. Both swab and saliva were positive in 19 (54.2%) patients, while 7 (20.0%) patients had swab positive/saliva negative results. There were 9 (25.7%) patients with saliva positive/swab negative result and this included 5 asymptomatic COVID-19 patients undergoing repeat screening. Using the swab as the reference gold standard, the sensitivity and specificity of saliva were 73.1% (95% CI 52.2– 88.4%) and 97.6% (95% CI 95.5– 98.9%) while the positive and negative predictive values were 67.9% (95% CI 51.5– 80.8%) and 98.1% (95% CI 96.5– 99.0%), respectively.Conclusion: The findings suggest good diagnostic accuracy for saliva and feasibility of utilization of specimen without transport media for SARS-CoV-2 RT-PCR. Saliva represents a potential specimen of choice in community settings and population-based screening.Keywords: SARS-CoV-2, nasopharyngeal swab, molecular test, population-based screening, saliva