Timely and accurate detection of SARS-CoV-2, the causative agent of COVID-19, is necessary in order to control the ongoing pandemic. Typically, reverse transcription polymerase chain reaction test (RT-PCR) is used for pathogen identification, but obtaining the results can be costly and time-consuming. A new study, published in BMC Infectious Diseases, investigated whether detection dogs could be trained to detect SARS-CoV-2 as a reliable screening method1.
In the study titled “Scent dog identification of samples from COVID-19 patients – a pilot study”, eight detection dogs were trained for a period of one week to detect saliva or tracheobronchial secretions of SARS-CoV-2 infected patients in a randomised, double-blinded and controlled study.
Saliva samples and tracheobronchial secretion samples were collected from hospitalised COVID-19 patients that showed clinical signs and were diagnosed as SARS-CoV-2 positive using nasopharyngeal swabs. Negative control samples were obtained from SARS-CoV-2 RT-PCR negative patients with no previous history of COVID-19 or other recent upper respiratory tract infection. Samples from COVID-19 patients were inactivated using beta propiolactone (BPL) in order to safeguard the dogs and their handlers from infection. A Detection Dog Training System (DDTS) was used to train and test the dogs; dogs were automatically rewarded for indicating on the positive sample. The dogs achieved an overall diagnostic sensitivity of 82.63% and specificity of 96.35%.
Professor Ian Ramsey, BSAVA President said: “The results of this pilot study are promising, though there is a clear need for further, well-designed research in this area. The results boasted a high test specificity, which is important in avoiding false negative results and curbing the spread of the virus. The test sensitivity, however, was lower and there was some intra- and inter-dog variability. The inclusion criteria for positive SARS-CoV-2 samples were non-specific, and did not account for differences such as severity of symptoms, disease state or viral load. Future studies should therefore focus on whether these factors may impact test sensitivity.”
The full article, which is Open Access, can be read online here.
1P. Jendrny, C. Schulz, F. Twele, et al. Scent dog identification of samples from COVID-19 patients – a pilot study. BMC Infect Dis 20, 536 (2020). https://doi.org.10.1186/s12879-020-05281-3