At around 5 pm, scent dogs sniff samples collected from different passengers inside a Covid-19 detection site at Kigali International Airport to identify the virus causing the disease.
That was on June 5, 2021 when Rwanda launched a three-month trial of using sniffer dogs in the testing for coronavirus in a bid that health experts say is likely to strengthen the country’s efforts to control the virus spread, and it can contribute to enabling early treatment for those who have contracted it.
The move implies that you could be tested for Covid-19 without the insertion of a swab into your nostril or mouth, rather a canine scenting the virus in your bodily secretions such as sweat sample – and without contact with you.
Currently, five trained sniffer dogs are being used to detect the virus from samples taken from passengers at the Kigali International Airport. Imported from the Netherlands, the dogs are trained to recognise a distinctive odour produced by people with the virus.
The Rwanda Biomedical Centre (RBC) said that the dogs can detect Covid-19 within an accuracy close to that of the polymerase chain reaction (PCR) test in about one minute – preliminary results showed that they can identify Covid-19 with an efficacy rate of up to 94 percent.
PCR is a common laboratory technique used to test the virus, consisting mainly of DNA amplification. Currently, PCR results in Rwanda are available within eight hours.
The initiative under consideration aims to reduce the time and cost of testing Covid-19 at the airport, and ultimately at mass gatherings, according to RBC.
Scientists who are proponents of this initiative suggest that scent dogs could help to control the pandemic because they can screen thousands of samples an hour in busy places such as airports, markets, sports stadiums, borders and schools. They argue that they are providing a cheap, fast and effective alternative technique of testing people for the virus.
How does the technology work?
Before deployment, the dogs receive training which can take up to 400 hours – almost 16 days – in order to increase their sniffing skills, according to Leon Mutesa, Professor of Human Genetics at the University of Rwanda.
Mutesa indicated that it can take a dog around three minutes to detect between 20 and 50 samples, adding that they also receive refresher courses daily in line with honing their skills.
According to RBC, passengers arriving at the airport will not be in contact with the sniffer dogs, rather will be asked for consent to participate in this pilot and receive sample cotton patches.
Mutesa said that a sample cotton tissue is used to collect sweat or moisture from the person in question such as through wiping it on their armpit, or forehead – and the person is given the tissue to do that by themselves.
The collected samples will then be taken – by data collectors – to the sniffing cabin set up in a separate area.
The dog detects the virus from the containers, each bearing the names or brief identification of the respective person.
Unlike in the explosive or drug detection where the dog squats, for Covid-19, it stops (moving) when it senses its presence in a sample.
Canine training
The dogs are trained with the support of a device called detection dog training system (DDTS), an electronic piece of equipment for dog training in the fields of odour conditioning, differentiation and indication. It was manufactured by German firm Kynoscience.
It can be used for the training on various odorous substances from the service sector such as explosives and drugs, the medical sector such as bacteria or viruses, but also for training on protected animals.
This device can present samples in a randomised automated manner without trainer interference. It is composed of seven scent holes where the dog can carry out the search. Only one container is presented in each sniffing hole at any given time.
The containers are covered with grids, which allowed the odour to escape and reach the sniffing hole. Each tube extension is identical and shaped in a way that it prevents dogs from physical contact with the samples.
After the indication of the hole with the positive sample, the dog is automatically rewarded by the device with feed or ball. While the dog picks up the reward, another scent hole is automatically activated.
Currently, Finland, Lebanon and the United Arab Emirates are countries that started piloting dogs in detecting Covid-19, while Rwanda is the first country to do so in Africa.
So far, 350,400 Rwandans – or less than 3 percent of Rwandans’ estimated 12 million population, have been vaccinated against Covid-19, while over 1.46 million or 12 percent of Rwandans have been tested for the disease, according to information from the Ministry of Health.