Table 1.
Summary of recent studies comparing SARS-CoV-2 detection in saliva and nasopharyngeal swabs in children
| Author Country |
No. of participants (No. positivea) | Age | Severity of disease (Setting) | Saliva collection method (Volume) | Platform | Saliva sensitivity compared with NPS | Saliva sensitivity compared with all positive tests | Positive |
Comments | ||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Total | NPS only | Saliva only | |||||||||
| Al Suwaidi et al. 2021 [5] UAE |
476 (87 positive) |
Mean 10.8 y Range 3–18 y |
39/87 mild symptoms (Screening clinic) |
Dribble pot (1–3 mL) 200 μL undiluted saliva |
EZ1 extraction (Qiagen) Allplex 2019-nCoV Assay kit (Seegene) (N, E and RdRp genes) Positive = more than two genes detected; ‘presumptive positive’ = E gene detected |
71/81 (88%) | 77/87 (89%) | 87 | 10 | 6 | Ct values significantly higher in saliva |
| Borghi et al. 2020 [11] Italy |
109 (27 positive) |
Range 0-17y | Not stated (Attending hospital) |
Sterile dental role | SalivaDirect™ process [19] using N1, RdRp primers/probes (CDC) Applied Biosystem 7500 Fast platform Positive = N1-gene detected at Ct < 40 |
20/21 (95%) | 26/27 (96%) | 27 | 1 | 6 | |
| Yee et al. 2021 [15] USA |
43 cases <18 y positive Part of larger study |
Median 12 y Range 4–18 y |
Variable (Inpatients, outpatients and household contacts) |
Dribble pot (3 mL) 250 μL undiluted saliva |
Applied Biosystems MagMAX extraction kit (ThermoFisher) TaqPath COVID-19 Combo kit (ThermoFisher) Positive = one or more of N, S and ORF-1 genes |
29/38 (76%) | 34/43 (79%) | 43 | 9 | 5 | Performance superior for saliva in asymptomatic compared with symptomatic children |
| Han et al. 2020 [8] Korea |
(11 positive) | Median 6.5 y Range 27 d, 16 y |
9 mild symptoms; 3 asymptomatic | Not stated | Allplex 2019-nCoV Assay kit (Seegene) (N, E and RdRp genes) |
8/11 (73%) | 8/11 (73%) | 11 | N/A | N/A | Saliva positivity declined rapidly after first week |
| Chong et al. 2021 [9] Singapore |
(18 positive) | Mean 6.6 y IQR 1.8–11 y |
6 symptomatic; 12 asymptomatic | Dribble pot (minimum 0.5 mL) | Extraction method not stated RT-PCR E gene |
52.9% (day 4–7 of illness) | N/A | 18 | N/A | N/A | Ct values higher in saliva. Saliva positivity declined rapidly over first week |
| Guzman-Ortiz et al. 2021 [12] Mexico |
156 (23 positive) |
Range 5–18 y | 22 symptomatic 1 asymptomatic |
Spit five times into sterile tube | QIAmp Viral RNA mini kit (Qiagen) extraction GeneFinder COVID-19 PLUS RealAmp Kit (Elitech) |
14/17 (82%) | 20/23 (87%) | 23 | 3 | 6 | |
Abbreviations: N/A, not available; NPS, nasopharyngeal swab; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; UAE, United Arabe Emirates.
a
In NPS or saliva.