ISSN: 2474-9222
Authors: Dominique Grandjean*, Dana Humaid Al Marzooqi, Clothilde Lecoq-Julien, Quentin Muzzin1, Hamad Katir Al Hammadi, Guillaume Alvergnat, Kalthoom Mohammad Al Blooshi, Salah Khalifa Al Mazrouei, Mohammed Saeed Alhmoudi, Faisal Musleh Al Ahbabi, Yasser Saifallah Mohammed, Nasser Mohammed Alfalasi, Noor Majed Almheiri, Sumaya Mohamed Al Blooshi and Loïc Desquilbet
This study aimed to evaluate the sensitivity of 21 dogs belonging to different united arab emirate administrations, trained for covid-19 olfactory detection. The study involved 17 explosives detection dogs, two cadaver detection dogs and two dogs with no previous detection training. Training lasted two weeks before starting the validation protocol. Sequential five and sevencone line-ups were used with axillary sweat samples from 151 symptomatic covid-19 individuals (sars-cov-2 pcr positive) and from 110 asymptomatic covid-19 negative individuals (sars-cov-2 pcr negative). Each line-up had one positive sample and at least one negative sample. The dog had to mark the positive sample, randomly positioned behind one of the cones. The dog, handler and data recorder were blinded to the positive sample location. The calculated overall sensitivities were between 71% and 79% for three dogs, between83% and 87% for three other dogs and equal to or higher than 90% for the remaining 15 dogs (more than two thirds of the 21 dogs). After calculating the overall sensitivity for each dog using all lineups, “matched†sensitivities were calculated only including line-ups containing covid-19 positive and negative samples strictly comparable on confounding factors such as diabetes, anosmia, asthma, fever, body pain, diarrhoea, sex, hospital, method of sweat collection and sampling duration. Most of the time, the sensitivities increased after matching. Pandemic conditions in the U.A.E.., associated with the desire to use dogs as an efficient mass-pretesting tool has already led to the operational deployment of the study dogs. Future studies will focus on comparatives fields-test results including the impact of the main covid-19 comorbidities and other respiratory tract infections.
Keywords: Dogs; RT-PCR; Olfactory ; Covid-19
