tetano
Editor, Senior Moderator
J Breath Res
. 2022 Mar 14.
doi: 10.1088/1752-7163/ac5d8c. Online ahead of print.
Biomedical detection dogs for the identification of SARS-CoV-2 Infections from axillary sweat and breath samples
Philippe Devillier[SUP] 1 [/SUP], Capucine Gallet[SUP] 2 [/SUP], Hélène Salvator[SUP] 3 [/SUP], Clothilde Julien[SUP] 2 [/SUP], Emmanuel Naline[SUP] 3 [/SUP], Didier Roisse[SUP] 4 [/SUP], Clément Levert[SUP] 5 [/SUP], Erwan Breton[SUP] 5 [/SUP], Arnaud Galtat[SUP] 5 [/SUP], Sandra Decourtray[SUP] 6 [/SUP], Laura Prevel[SUP] 7 [/SUP], Stanislas Grassin-Delyle[SUP] 8 [/SUP], Dominique Grandjean[SUP] 2 [/SUP]
Affiliations
Abstract
A PCR test of a nasal swab is still the "gold standard" for detecting a SARS-CoV-2 infection. However, PCR testing could be usefully complemented by non-invasive, fast, reliable, cheap methods for detecting infected individuals in busy areas (e.g. airports and railway stations) or remote areas. Detection of the volatile, semivolatile and non-volatile compound signature of SARS-CoV-2 infection by trained sniffer dogs might meet these requirements. Previous studies have shown that well-trained dogs can detect SARS-CoV-2 in sweat, saliva and urine samples. The objective of the present study was to assess the performance of dogs trained to detect the presence of SARS-CoV-2 in axillary-sweat-stained gauzes and on expired breath trapped in surgical masks. The samples were provided by individuals suffering from mild-to-severe coronavirus disease 2019 (COVID-19), asymptomatic individuals, and individuals vaccinated against COVID-19. Results: Seven trained dogs tested on 886 presentations of sweat samples from 241 subjects and detected SARS-CoV-2 with a diagnostic sensitivity (relative to the PCR test result) of 89.6% (95% confidence interval (CI): 86.4-92.2%) and a specificity of 83.9% (95% CI: 80.3-87.0%) - even when people with a low viral load were included in the analysis. When considering the 207 presentations of sweat samples from vaccinated individuals, the sensitivity and specificity were respectively 85.7% (95% CI: 68.5-94.3) and 86.0% (95% CI: 80.2-90.3%). The likelihood of a false-positive result was greater in the two weeks immediately after COVID-19 vaccination. Four of the seven dogs also tested on 262 presentations of mask samples from 98 subjects; the diagnostic sensitivity was 83.1% (95% CI: 73.2-89.9) and the specificity was 88.6% (95% CI: 83.3-92.4%). There was no difference (McNemar's test P=0.999) in the dogs' abilities to detect the presence of SARS-CoV-2 in paired samples of sweat-stained gauzes vs. surgical masks worn for only 10 minutes. Conclusion: Our findings confirm the promise of SARS-CoV-2 screening by detection dogs and broaden the method's scope to vaccinated individuals and easy-to-obtain face masks, and suggest that a "dogs + confirmatory rapid antigen detection tests" screening strategy might be worth investigating.
Keywords: COVID-19; Scent detection dogs; breath; public health; sweat; vaccine; volatile organic compound.
. 2022 Mar 14.
doi: 10.1088/1752-7163/ac5d8c. Online ahead of print.
Biomedical detection dogs for the identification of SARS-CoV-2 Infections from axillary sweat and breath samples
Philippe Devillier[SUP] 1 [/SUP], Capucine Gallet[SUP] 2 [/SUP], Hélène Salvator[SUP] 3 [/SUP], Clothilde Julien[SUP] 2 [/SUP], Emmanuel Naline[SUP] 3 [/SUP], Didier Roisse[SUP] 4 [/SUP], Clément Levert[SUP] 5 [/SUP], Erwan Breton[SUP] 5 [/SUP], Arnaud Galtat[SUP] 5 [/SUP], Sandra Decourtray[SUP] 6 [/SUP], Laura Prevel[SUP] 7 [/SUP], Stanislas Grassin-Delyle[SUP] 8 [/SUP], Dominique Grandjean[SUP] 2 [/SUP]
Affiliations
- PMID: 35287115
- DOI: 10.1088/1752-7163/ac5d8c
Abstract
A PCR test of a nasal swab is still the "gold standard" for detecting a SARS-CoV-2 infection. However, PCR testing could be usefully complemented by non-invasive, fast, reliable, cheap methods for detecting infected individuals in busy areas (e.g. airports and railway stations) or remote areas. Detection of the volatile, semivolatile and non-volatile compound signature of SARS-CoV-2 infection by trained sniffer dogs might meet these requirements. Previous studies have shown that well-trained dogs can detect SARS-CoV-2 in sweat, saliva and urine samples. The objective of the present study was to assess the performance of dogs trained to detect the presence of SARS-CoV-2 in axillary-sweat-stained gauzes and on expired breath trapped in surgical masks. The samples were provided by individuals suffering from mild-to-severe coronavirus disease 2019 (COVID-19), asymptomatic individuals, and individuals vaccinated against COVID-19. Results: Seven trained dogs tested on 886 presentations of sweat samples from 241 subjects and detected SARS-CoV-2 with a diagnostic sensitivity (relative to the PCR test result) of 89.6% (95% confidence interval (CI): 86.4-92.2%) and a specificity of 83.9% (95% CI: 80.3-87.0%) - even when people with a low viral load were included in the analysis. When considering the 207 presentations of sweat samples from vaccinated individuals, the sensitivity and specificity were respectively 85.7% (95% CI: 68.5-94.3) and 86.0% (95% CI: 80.2-90.3%). The likelihood of a false-positive result was greater in the two weeks immediately after COVID-19 vaccination. Four of the seven dogs also tested on 262 presentations of mask samples from 98 subjects; the diagnostic sensitivity was 83.1% (95% CI: 73.2-89.9) and the specificity was 88.6% (95% CI: 83.3-92.4%). There was no difference (McNemar's test P=0.999) in the dogs' abilities to detect the presence of SARS-CoV-2 in paired samples of sweat-stained gauzes vs. surgical masks worn for only 10 minutes. Conclusion: Our findings confirm the promise of SARS-CoV-2 screening by detection dogs and broaden the method's scope to vaccinated individuals and easy-to-obtain face masks, and suggest that a "dogs + confirmatory rapid antigen detection tests" screening strategy might be worth investigating.
Keywords: COVID-19; Scent detection dogs; breath; public health; sweat; vaccine; volatile organic compound.