Research letter exploring the efficacy of a program using canine scent screening for COVID-19 in school children as a rapid non-invasive, low cost and environmentally responsible method compared to a resource intensive universal antigen testing program. Two dogs underwent 2-month laboratory scent training to detect volatile organic compounds associated with COVID-19 infections resulting in 95% sensitivity and specificity in detecting the virus. Combined antigen and field-testing of 1558 student in 27 schools between April and May 2022 resulted in 3897 combined screenings. Sniffing the feet and ankles of students standing 6 feet apart, the dogs detected 85 infections, missed 18 and signaled 383 false positives resulting in a sensitivity of 83% and a specificity of 90% with antigen testing used as backup. Field testing, while rapid and low impact, has limitations but canine scent testing for COVID-19 and other pathogens should be considered where large scale screening is needed and resources are limited.
SAB Comment: The authors acknowledge the fact that one of the limitations of this study was the low incidence of infections during the test period. Not addressed is the potential need for re-training of dogs as new variants of the virus appear, emitting different volatile compounds.