Saliva Is a Promising Alternative Specimen for the Detection of SARS-CoV-2 in Children and Adults

Abstract

Testing efforts for SARS-CoV-2 have been burdened by the scarcity of testing materials and personal protective equipment for health care workers. The simple and painless process of saliva collection allows for widespread testing, but enthusiasm is hampered by variable performance compared to nasopharyngeal swab (NPS) samples. We prospectively collected paired NPS and saliva samples from a total of 300 unique adult and pediatric patients. SARS-CoV-2 RNA was detected in 32.2% (97/300) of the individuals using the TaqPath COVID-19 Combo Kit (Thermo Fisher). Performance of saliva and NPS were compared against the total number of positives regardless of specimen type. The overall concordance for saliva and NPS was 91.0% (273/300) and 94.7% (284/300), respectively. The positive percent agreement (PPA) for saliva and NPS was 81.4% (79/97) and 89.7% (87/97), respectively. Saliva detected 10 positive cases that were negative by NPS. In symptomatic and asymptomatic pediatric patients not previously diagnosed with COVID-19, the performances of saliva and NPS were comparable (PPA: 82.4% vs 85.3%). The overall PPA for adults were 83.3% and 90.7% for saliva and NPS, respectively, with saliva detecting 4 cases less than NPS. However, saliva performance in symptomatic adults was identical to NPS (PPA of 93.8%). With lower cost and self-collection capabilities, saliva can be an appropriate alternative sample choice to NPS for detection of SARS-CoV-2 in children and adults.

Performance of RT-PCR on saliva specimens compared to nasopharyngeal swabs for the detection of SARS-CoV-2 in children: A prospective comparative clinical trial

“…Recent studies 23–25 suggest that no cultivable viable virus is detected from patients with VLs under the threshold of 10 4 copies/ml. Altogether ours and others findings suggest 8 that children detected SARS-CoV-2 negative from saliva samples presented VLs under the threshold of 10 4 copies/ml from their NP and were thereby potentially less contagious. The use of saliva as an alternative to NP for SARS-CoV-2 detection in children would thus limit quarantine measures to most contagious children 26 .…”

“…With more than twice as many children included 8 , this study is by far, the largest cohort reporting on the performance of saliva specimens in children. As supported by another study including children 8 and other studies conducted in adults 10,19 , a detection rates slightly lower of SARS-COV-2 were reported from saliva as compared to NP specimens, yet still supporting the use of saliva as an alternative to NP swabs in children. Moreover, our findings are in line with the RADICO study conducted in symptomatic adults, that used the same saliva collection approach 10 .…”

“…Pediatric evidence for the use of saliva specimens by RT-PCR for detection of SARS-CoV-2 remains weak with sensitivities varying from 52.9% up to 85.0% reported from small sample sizes when using NP as the gold standard. 8,9 This ancillary study of the adult RADICO project 10 aims to prospectively compare the paired saliva and NP samples collected from symptomatic children consulting in outpatient settings for the detection of SARS-CoV-2. The secondary objectives were to compare discordant NP and saliva RT-PCR findings as well as their VL.…”

Salivette, a relevant saliva sampling device for SARS-CoV-2 detection

“…Although salivary tests for SARS-CoV-2 detection are currently used in routine diagnostic laboratories for patient investigations in several countries from Asia, America and Europe [12,[36][37][38], this tool remains under progress for validation in France [39]. The insufficient sensitivity of salivary tests based on molecular approaches (e.g.…”

“…Moreover, nasal swab is contraindicated for people with blood clotting diseases or deviated septum, for example [10]. Swab sampling is technically not evident to succeed in every case, notably not on very young children or in self-collection [11,12]. Then, this suboptimal collection may reduce test sensitivity, and the recourse to repeat sampling is not infrequent [13].…”