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Comment
. 2021 Oct;83(4):496-522.
doi: 10.1016/j.jinf.2021.07.012. Epub 2021 Jul 25.

Comparison of self-collected mouth gargle with deep-throat saliva samples for the diagnosis of COVID-19: Mouth gargle for diagnosis of COVID-19

Christopher Kc Lai  1 , Grace Cy Lui  2 , Zigui Chen  1 , Yuk-Yam Cheung  3 , Kwok Chu Cheng  3 , Agnes Sy Leung  4 , Rita Wy Ng  1 , Jo Lk Cheung  1 , Apple Cm Yeung  1 , Wendy Cs Ho  1 , Kate C Chan  4 , David Sc Hui  5 , Dominic Nc Tsang  3 , Paul Ks Chan  6
Affiliations
Comment

Comparison of self-collected mouth gargle with deep-throat saliva samples for the diagnosis of COVID-19: Mouth gargle for diagnosis of COVID-19

Christopher Kc Lai et al. J Infect. 2021 Oct.
No abstract available

Keywords: COVID-19; Diagnosis, screening; Gargle; Mouthwashes; Saliva; Sars-cov-2.

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Conflict of interest statement

Declaration of Competing Interest None declared

Figures

Fig. 1
Fig. 1
Positive rates of SARS-CoV-2 RNA detection between mouth gargle and saliva samples using four different assays in three different laboratories Reference Laboratory (Cobas 6800) positive rate for mouth gargle: 96.3% (95% CI 90.0–98.6), and DTS: 95.4% (95% CI 89.7–98.0). Reference Laboratory (GeneXpert) positive rate for mouth gargle: 94.5% (95% CI: 88.5–97.5), and DTS: 96.3% (95% CI: 90.9–98.6). Reference Laboratory (In-house method) positive rate for mouth gargle: 95.4% (95% CI 89.7–98.0), and DTS: 96.3% (95% CI 90.9–98.6). University Laboratory A (In-house method) positive rate of for mouth gargle: 89.9% (95% CI 82.8–94.2), and DTS 93.6 (95% CI 87.3–96.9). DTS – Deep-throat saliva samples; Gargle – mouth gargle samples. Fisher test was used to assess the difference in positive rates between detection assays and/or specimens. The 95% confidence interval (CI) was calculated using epi.conf (ctype=“prop.single") in epiR.
Fig. 2
Fig. 2
Comparison of diagnostic yield between sample types, assays, and laboratories A. Comparison of diagnostic yield of the 109 mouth gargle and DTS sample pairs by test method. Midline: median; Box: interquartile range; DTS, Deep-throat saliva; Gargle, mouth gargle. **** p ≤ 0.0001. Comparisons of viral concentration between detection assays and/or specimens were performed using non-parametric Mann-Whitney Wilcoxon rank-sum test (unpaired) or Wilcoxon signed rank test (paired). B. Correlation analysis between 109 mouth gargle and DTS sample pairs by test method. Correlation performed by Spearman's correlation index; R2adj, Adjusted R-squared. Spearman's rho and linear regression were used to evaluate their associations. A two-sided p value of < 0.05 was considered statistically significant. C - Inter-laboratory comparison of Cobas 6800 and GeneXpert of 26 paired samples by Reference Laboratory and University Laboratory B. Correlation performed by Spearman's correlation index; R2adj, Adjusted R-squared. DTS – deep-throat saliva; Gargle – mouth gargle. Spearman's rho and linear regression were used to evaluate their associations. A two-sided p value of < 0.05 was considered statistically significant. D - Inter-assay comparison of 26 paired samples by analyzing E genes detection by Cobas 6800 and Genexpert. Midline: median; Box: interquartile range; DTS – deep-throat saliva; Gargle – mouth gargle. Comparisons of viral concentration between detection assays and/or specimens were performed using non-parametric Mann-Whitney Wilcoxon rank-sum test (unpaired) or Wilcoxon signed rank test (paired). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
Fig. 2
Fig. 2
Comparison of diagnostic yield between sample types, assays, and laboratories A. Comparison of diagnostic yield of the 109 mouth gargle and DTS sample pairs by test method. Midline: median; Box: interquartile range; DTS, Deep-throat saliva; Gargle, mouth gargle. **** p ≤ 0.0001. Comparisons of viral concentration between detection assays and/or specimens were performed using non-parametric Mann-Whitney Wilcoxon rank-sum test (unpaired) or Wilcoxon signed rank test (paired). B. Correlation analysis between 109 mouth gargle and DTS sample pairs by test method. Correlation performed by Spearman's correlation index; R2adj, Adjusted R-squared. Spearman's rho and linear regression were used to evaluate their associations. A two-sided p value of < 0.05 was considered statistically significant. C - Inter-laboratory comparison of Cobas 6800 and GeneXpert of 26 paired samples by Reference Laboratory and University Laboratory B. Correlation performed by Spearman's correlation index; R2adj, Adjusted R-squared. DTS – deep-throat saliva; Gargle – mouth gargle. Spearman's rho and linear regression were used to evaluate their associations. A two-sided p value of < 0.05 was considered statistically significant. D - Inter-assay comparison of 26 paired samples by analyzing E genes detection by Cobas 6800 and Genexpert. Midline: median; Box: interquartile range; DTS – deep-throat saliva; Gargle – mouth gargle. Comparisons of viral concentration between detection assays and/or specimens were performed using non-parametric Mann-Whitney Wilcoxon rank-sum test (unpaired) or Wilcoxon signed rank test (paired). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
Fig. 2
Fig. 2
Comparison of diagnostic yield between sample types, assays, and laboratories A. Comparison of diagnostic yield of the 109 mouth gargle and DTS sample pairs by test method. Midline: median; Box: interquartile range; DTS, Deep-throat saliva; Gargle, mouth gargle. **** p ≤ 0.0001. Comparisons of viral concentration between detection assays and/or specimens were performed using non-parametric Mann-Whitney Wilcoxon rank-sum test (unpaired) or Wilcoxon signed rank test (paired). B. Correlation analysis between 109 mouth gargle and DTS sample pairs by test method. Correlation performed by Spearman's correlation index; R2adj, Adjusted R-squared. Spearman's rho and linear regression were used to evaluate their associations. A two-sided p value of < 0.05 was considered statistically significant. C - Inter-laboratory comparison of Cobas 6800 and GeneXpert of 26 paired samples by Reference Laboratory and University Laboratory B. Correlation performed by Spearman's correlation index; R2adj, Adjusted R-squared. DTS – deep-throat saliva; Gargle – mouth gargle. Spearman's rho and linear regression were used to evaluate their associations. A two-sided p value of < 0.05 was considered statistically significant. D - Inter-assay comparison of 26 paired samples by analyzing E genes detection by Cobas 6800 and Genexpert. Midline: median; Box: interquartile range; DTS – deep-throat saliva; Gargle – mouth gargle. Comparisons of viral concentration between detection assays and/or specimens were performed using non-parametric Mann-Whitney Wilcoxon rank-sum test (unpaired) or Wilcoxon signed rank test (paired). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
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