Dog noses are great Covid-19 detectors, according to numerous laboratory studies, and Covid detection dogs have already started working at airports in other countries and at some events in the US, like a Miami Heat basketball game.
However, some public health and sniffer dog training experts say more information and planning is needed to ensure they are accurate in real-life situations.
"There are no national standards" for scented dogs, said Cynthia M. Otto, director of the Penn Vet Working Dog Center at the University of Pennsylvania School of Veterinary Medicine and one of the authors of a new article on the use of scented dogs in Covid detection.
And while private groups certify drug sniffing and bomb and rescue dogs, there are no similar medical detection programs in place in the journal Disaster Medicine and Public Health Preparedness, according to the new paper.
Lois Privor-Dumm, a public health researcher at Johns Hopkins University and lead author of the article, said there is no question that dogs have great potential in medical fields. But she wants to investigate how they could be used on a large scale, for example by the government.
“What are all the ethical considerations? What are the regulatory considerations? How practical is that? ”She asked. Not only the quality of detection, but also logistics and cost would be central to any widespread application, as with any public health intervention.
Quality control is a first step and a big one. Medical odor detection is more complicated than detecting drugs or bombs, said Dr. Otto. A dog working to detect drugs or explosives in an airport has a consistent context and a fairly simple target odor. With Covid detection, researchers know that dogs can differentiate between sweat and urine from an infected person. But they don't know what chemicals the dog is identifying.
Because human smells vary, medical sniffer dogs must be trained on many different people. "We have all races and ages and diets and all these things that make people smell," said Dr. Otto.
The symptoms of many illnesses are similar to those of Covid, and dogs smelling smells related to fever or pneumonia would be ineffective. Therefore, according to Dr. Otto "include many people who are negative but might have a cough or a fever or other things". Obviously, if the dogs mistake flu for Covid, that would be a critical mistake.
Dogs can also be trained on sweat, saliva, or urine. In the United Arab Emirates, the dogs worked with urine samples. In Miami they just walked past a number of people.
All positive cases of Covid infection that the dogs detect are usually compared with today's gold standard for confirming the presence of the coronavirus, a P.C.R. Exam. However, a review of the research published last week concluded that dogs fared better than the test.
But these are experimental results. Dogs are good at remotely detecting explosives and other substances, but so far, Dr. Otto that she is not aware of any published research showing the accuracy of dogs who sniff people in a line instead of urine or sweat.
If the government were to officially conduct or approve dogs for Covid detection, some standards would need to be set for how dogs should be trained and their performance assessed. Dr. Otto is on a committee of the National Institute of Standards and Technology that is now meeting to develop standards for scent detection dogs in a variety of situations, including detecting Covid.
She said even if the standards were clearly set, finding enough dogs to do widespread odor detection was another hurdle. Trained dogs are not easy to come by. “We have a shortage of bomb detection dogs in this country. We have been dealing with this for years, ”she says.
Dogs can be retrained from one smell to another, but that can be tricky. “Some countries take their bomb trained dogs and train them on Covid. But you know, all you have to do is think of an airport, if you have a dog that sniffs both covid and bombs and it alerts you, then what do you have? "
Well-trained dogs are also costly and require paid, well-trained human handlers. According to the report, dogs can cost $ 10,000 and odor training can cost $ 16,000 per dog. For example, the Transportation Security Administration has a $ 12 million explosive detection dog and handler training facility in San Antonio and estimates the cost of training dogs and handlers at $ 33,000 for explosives detection and $ 46,000 for passenger control.
All of these questions will determine how dogs will be used in the future. Your ability is there. "I think they absolutely can," said Dr. Otto. "This is how we implement them."