Table 2.
Detection of SARS-CoV-2 in samples of saliva and nasopharyngeal swabs: (A) paired samples; (B) saliva samples only; (C) saliva only in the present study.
| A | Paired samples |
||||
|---|---|---|---|---|---|
| Country | Study population | Paired samples | Viral genes | Concordance % | Reference |
| Australia | Ambulatory patients | 522 | ORF1a, ORF8 | 84.6 | (Williams et al., 2020) |
| Canada | Hospitalized patients | 91 | RdRp, E, N | 61.0 | (Jamal et al., 2020) |
| China | Ambulatory patients | 229 | E | 76.0 | (Cheuk et al., 2020) |
| China | Hospitalized patients | 58 | RdRp/Hel, E, N2 | 84.5 | (Chen et al., 2020) |
| China | Patients from 12 independent cohorts | 944 | S, E, ORF1ab, N, RdRp, 5′UTR | 92.1 | (Zhu et al., 2020) |
| China | Hospitalized patients | 95 | E, RdRp | 78.9 | (Leung Chi‐man et al., 2021) |
| Japan | Ambulatory patients | 76 | N | 97.4 | (Iwasaki et al., 2020) |
| Mexico | Ambulatory patients | 253 | E | 78.6 | (Moreno-Contreras et al., 2020) |
| Thailand | Hospitalized patients | 200 | ORF1ab, N | 97.5 | (Pasomsub et al., 2020a) |
| USA | Hospitalized patients and asymptomatic healthcare workers | 29 | N1, N2 | 79.0 | (Wyllie et al., 2020) |
| USA | Ambulatory patients | 91 | N1, N2 | 94.0 | (Miller et al., 2020) |
| Mexico | Asymptomatic healthcare and office workers | 2107 | N1, N2 | 97.9 | Our study |
| B | Saliva samples only |
||||
|---|---|---|---|---|---|
| Country | Study population | Saliva samples | Viral genes | Positivity % | Reference |
| China | Hospitalized patients | 12 | S | 91.7 | (To et al., 2020a) |
| China | Hospitalized patients | 18 | E | 84.0 | (Hung et al., 2020) |
| Italy | Hospitalized patients | 25 | 5′UTR | 100.0 | (Azzi et al., 2020) |
| Japan | Hospitalized patients | 103 | N1, N2, ORF1, E | 93.4 | (Ikeda et al., 2020) |
| C | Saliva only in the present study |
|||||
|---|---|---|---|---|---|---|
| Setting | Total samples | Number of tests | Positive samples | Positivity (%) | Reduction in testing costs (%)a | Reduction in total sample collection direct costs (USD)b, c |
| Asymptomatic office workers | 3983 | 1032 | 26 | 0.65 | 74 | $10 754.50 |
| Asymptomatic healthcare personnel | 2126 | 870 | 98 | 4.6 | 59 | $5740.20 |
| Symptomatic office workers | 846 | 846 | 67 | 7.9 | 0 | $2284.20 |
RdRp, RNA-dependent RNA polymerase; RdRp/Hel, RNA -dependent RNA polymerase/helicase; ORF1, open reading frame 1 (a,b); ORF8, open reading frame 8; E, envelope; N, nucleocapsid.
a
Cost reduction was calculated considering the number of tests necessary to identify the positive individuals in the positive pools.
b
Sample collection direct cost: 3 USD vs 0.3 USD, nasopharyngeal and saliva, respectively.
c
The sample cost includes both direct and indirect costs.