Identifying SARS-COV-2 infected patients through canine olfactive detection on axillary sweat samples; study of observed sensitivities and specificities within a group of trained dogs
This article has been Reviewed by the following groups
Listed in
- Evaluated articles (ScreenIT)
Abstract
There is an increasing need for rapid, reliable, non-invasive, and inexpensive mass testing methods as the global COVID-19 pandemic continues. Detection dogs could be a possible solution to identify individuals infected with SARS-CoV-2. Previous studies have shown that dogs can detect SARS-CoV-2 on sweat samples. This study aims to establish the dogs’ sensitivity (true positive rate) which measures the proportion of people with COVID-19 that are correctly identified, and specificity (true negative rate) which measures the proportion of people without COVID-19 that are correctly identified. Seven search and rescue dogs were tested using a total of 218 axillary sweat samples (62 positive and 156 negative) in olfaction cones following a randomised and double-blind protocol. Sensitivity ranged from 87% to 94%, and specificity ranged from 78% to 92%, with four dogs over 90%. These results were used to calculate the positive predictive value and negative predictive value for each dog for different infection probabilities (how likely it is for an individual to be SARS-CoV-2 positive), ranging from 10–50%. These results were compared with a reference diagnostic tool which has 95% specificity and sensitivity. Negative predictive values for six dogs ranged from ≥98% at 10% infection probability to ≥88% at 50% infection probability compared with the reference tool which ranged from 99% to 95%. Positive predictive values ranged from ≥40% at 10% infection probability to ≥80% at 50% infection probability compared with the reference tool which ranged from 68% to 95%. This study confirms previous results, suggesting that dogs could play an important role in mass-testing situations. Future challenges include optimal training methods and standardisation for large numbers of detection dogs and infrastructure supporting their deployment.
Article activity feed
-
-
SciScore for 10.1101/2021.06.10.21257898: (What is this?)
Please note, not all rigor criteria are appropriate for all manuscripts.
Table 1: Rigor
Ethics IACUC: The protocol was approved by the committee on the ethics of animal experiments of the Ecole Nationale Vétérinaire
Consent: All individuals (COVID-19 positives and negatives) meeting these inclusion criteria were asked if they were willing to participate in the study and signed an individual informed consent form approved by the national ethics committee.
IRB: All individuals (COVID-19 positives and negatives) meeting these inclusion criteria were asked if they were willing to participate in the study and signed an individual informed consent form approved by the national ethics committee.Sex as a biological variable In order to remove potential confounding bias (i.e. high Se and Sp due … SciScore for 10.1101/2021.06.10.21257898: (What is this?)
Please note, not all rigor criteria are appropriate for all manuscripts.
Table 1: Rigor
Ethics IACUC: The protocol was approved by the committee on the ethics of animal experiments of the Ecole Nationale Vétérinaire
Consent: All individuals (COVID-19 positives and negatives) meeting these inclusion criteria were asked if they were willing to participate in the study and signed an individual informed consent form approved by the national ethics committee.
IRB: All individuals (COVID-19 positives and negatives) meeting these inclusion criteria were asked if they were willing to participate in the study and signed an individual informed consent form approved by the national ethics committee.Sex as a biological variable In order to remove potential confounding bias (i.e. high Se and Sp due to specific odour of COVID-19 positive and negative individuals not related to the presence or absence of SARS-Cov-2 [36, 72]), Se and Sp were also calculated separately in males, females, individuals younger and older than 50 years old, patients recruited from Foch and Rambouillet hospitals (hospitals from which the recruitment of COVID-19 positive patients was the highest), among samples of individuals who did not present the most frequently reported clinical signs (dyspnoea, fatigue, fever, dry cough, and muscular pain), among those who did not have the most frequently reported past or current diseases (hypertension and diabetes), and among those who were not treated by the most frequently reported drugs used (painkillers, anti-coagulant, anti-hypertension, anti-inflammatory, and antibiotics). Randomization During trials, all the cones contained COVID-19 negative and/or positive samples, and both the number of positive and negative samples and their position in the line-up were randomised, as recommended by Johnen [71], using a dedicated website (http://www.randomization.com), and double-blinded to the handler and his dog and to the data-recorder. Blinding not detected. Power Analysis not detected. Table 2: Resources
Software and Algorithms Sentences Resources Statistical analyses were performed using SAS® University Edition (SAS Institute Inc. SAS Institutesuggested: (Statistical Analysis System, RRID:SCR_008567)Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).
Results from LimitationRecognizer: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.Results from TrialIdentifier: No clinical trial numbers were referenced.
Results from Barzooka: We did not find any issues relating to the usage of bar graphs.
Results from JetFighter: We did not find any issues relating to colormaps.
Results from rtransparent:- Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
- Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
- No protocol registration statement was detected.
Results from scite Reference Check: We found no unreliable references.
-
