Toward the use of medical scent detection dogs for COVID-19 screening

Current testing for the presence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 virus), which causes the novel coronavirus 2019 (COVID-19) infection, is typically reliant upon collection of nasal swab samples from subjects. These tests (reverse transcription polymerase chain reaction [RT-PCR] and antigen) are intrusive, can take significant time to process, and can give deleterious false negative and false positive results. Alternative methods for COVID-19 testing and screening are being studied, including the use of trained scent detection dogs to detect volatile organic compounds (VOCs) associated with the COVID virus. In August 2020 and October 2020, the first author (T.D.) searched MEDLINE/PubMed, Cochrane Library, Google Scholar, and additional news articles using keyword phrases including "COVID scent dogs," "COVID sniffer dogs," and "COVID detection dog," returning a total of 13 articles, nine of which were duplicates. Four remaining peer-reviewed studies dedicated to determining the feasibility and efficacy of detecting and screening individuals who may be infected by the COVID-19 virus with scent detection dogs were then examined. In this narrative review, the authors describe the methodologies and results of the remaining four studies, which demonstrated that the sensitivity, specificity, and overall success rates reported by the summarized scent detection studies are comparable to or better than the standard RT-PCR and antigen testing procedures, meaning that scent detection dogs can likely be effectively employed to nonintrusively screen and identify individuals infected with the COVID-19 virus in hospitals, senior care facilities, schools, universities, airports, and even large public gatherings for sporting events and concerts.