Background: A previous study demonstrated the performance of the Salivette ® (SARSTEDT, Numbrecht, Germany) as a homogeneous saliva collection system to diagnose COVID-19 by RT-qPCR, notably for symptomatic and asymptomatic patients. However, for convalescent patients, the corroboration of molecular detection of SARS-CoV-2 in paired nasopharyngeal swabs (NPS) and saliva samples was unsatisfactory. Objectives: The aim of the present work was to assess the concordance level of SARS-CoV-2 detection between paired sampling of NPSs and saliva collected with Salivette ® at two time points, with ten days of interval. Results: A total of 319 paired samples from 145 outpatients (OP) and 51 healthcare workers (HW) were collected. Unfortunately, at day ten, 73 individuals were lost to follow-up, explaining some kinetic missing data. Due to significant waiting rates at hospitals, most of the patients ate and/or drank while waiting for their turn. Consequently, mouth washing was systematically proposed prior to saliva collection. None of the HW were diagnosed as SARS-CoV-2 positive using NPS or saliva specimens at both time points ( n = 95) by RT-qPCR. The virus was detected in 56.3% ( n = 126/224) of the NPS samples from OP, but solely 26.8% ( n = 60/224) of the paired saliva specimens. The detection of the internal cellular control, the human RNase P, in more than 98% of the saliva samples, underlined that the low sensitivity of saliva specimens (45.2%) for SARS-CoV-2 detection was not attributed to an improper saliva sample storing or RNA extraction. Conclusions: This work revealed that mouth washing decreased viral load of buccal cavity conducting to impairment of SARS-CoV-2 detection. Viral loads in saliva neo-produced appeared insufficient for molecular detection of SARS-CoV-2. At the time when saliva tests could be a rapid, simple and non-invasive strategy to assess large scale schoolchildren in France, the determination of the performance of saliva collection becomes imperative to standardize procedures.
【저자키워드】 SARS-CoV-2, Saliva, coronavirus, COVID-19 diagnosis, 【초록키워드】 COVID-19, virus, healthcare worker, hospitals, RNA extraction, Nasopharyngeal swab, SARS-CoV-2 detection, sensitivity, RT-qPCR, Convalescent patients, Concordance, Viral load, Germany, France, Follow-up, molecular, patients, diagnose, cellular, Outpatient, saliva test, kinetic, Non-invasive, individual, RNase P, impairment, positive, saliva specimens, NPs, collected, the patient, diagnosed, demonstrated, imperative, homogeneous, turn, saliva specimen, symptomatic and asymptomatic, 【제목키워드】 detection, mouth, washing, Impaired,