Why Does the United States Ignore the Possibility of Using Sniffer Dogs to Detect Covid in Mass Settings?

By Lambert Strether of Corrente.

I don’t know. By Hanlon’s Razor, because we’re dumb. So that’s it, that’s the post. Anyhow, I stan for sniffer dogs to detect Covid (Links May 5, 2020 and August 5, 2020, those being the examples Google allows me to find). And I keep seeing stories about them. So this will be a very simple post. First, I’m going to list all the real-world examples of sniffer dogs detecting Covid that I can find; some are pilots, some are fully implemented. Next, I’ll present the (few) studies I’ve been able to find on their effectiveness. Finally, I’ll briefly discuss the cost of Covid sniffer dogs, and their cost-effectiveness. First, to the examples.

The United States (March 18, 2021). The New York Post:

International researchers have claimed that well-trained dogs have the ability to correctly identify coronavirus patients at reported rates of 94% to 98%, according to some studies. If proven effective, they say these dogs could be an asset to public health officials, who could place the skilled sniffers in high-traffic hubs including airports, train terminals and public events.

Among the first to launch their canine-based coronavirus testing program: NASCAR. Race officials said Wednesday that they had hired the 360 K9 Group, based in Alabama and Florida, to monitor for infected guests during their most recent event — last Sunday’s Cup Series race at Atlanta Motor Speedway — and will continue the effort on a “trial basis” for Sunday’s Folds of Honor QuikTrip 500.

“We think that these dogs and this capability is going to allow us to rapidly confirm that all of those people entering the essential footprint on Sunday — that’s race teams, that’s NASCAR officials, that’s the vendors that work inside the garage — all those folks are COVID-free or not,” said Tom Bryant, NASCAR managing director of racing operations, in a statement on Nascar.com. “The ability to do that has kind of been the math problem that we have continuously tried to solve since March of last year.”

Thailand (March 17, 2021). From Reuters:

Thai sniffer dogs trained to detect COVID-19 in human sweat proved nearly 95% accurate during training and could be used to identify coronavirus infections at busy transport hubs within seconds, the head of a pilot project said.

“The dogs take only one to two seconds to detect the virus,” Professor Kaywalee Chatdarong, the leader of the project at the veterinary faculty of Thailand’s Chulalongkorn University, told Reuters.

“Within a minute, they will manage to go through 60 samples.”

The dogs can detect a volatile organic compound secreted in the sweat of COVID-19 sufferers, even in the absence of disease symptoms, the Thai researcher said.

Belgium (March 5, 2021). Brussels Times:

The KV Oostende football club, in coordination with K9 Detection Belgium, found that dogs could detect coronavirus in a person on the first day of infection, often a full week ahead of a traditional PCR test.

When trained dogs sniffed a swab that was taken from the armpit instead of up the nose, they were able to identify the presence of the coronavirus with an accuracy that was in line with the traditional PCR 99.5% of the time, according to De Standaard.

“There were players who tested negative via PCR, but were found to be positive with us [via the dogs]. Eight or nine days later, they turned out to be positive,” says the football club. “If they had followed our result, the infected player would have gone into quarantine earlier and the virus would not have spread further in the group of players.”

[Covid-sniffing dogs are already being used] by federal police in Belgium, who employ them in elderly care homes as well as airports.

The tracking dogs are unlikely to replace the PCR test in the short term, but the football club is hoping it could be a viable method for readmitting fans to games.

“Having a few thousand people take a PCR test before they are allowed to come to football is not financially and practically impossible,” the club points out. “We must take hold of every possibility to reopen our lives.”

Switzerland (March 3, 2021). ANI:

Geneva, March 3 (ANI/Xinhua): Researchers in Switzerland have launched a training trial to see if sniffer dogs can find out people infected with COVID-19.

Three dogs are being trained by researchers from Geneva University Hospitals (HUG) for four weeks by exposing to samples of sick and healthy people, after which the dogs will go through a sweat-sniffing test to see if they can identify infected individuals, said the hospitals in an online statement on Tuesday.

The study, as a collaboration among HUG, the largest university hospital in Switzerland, and the Swiss Army and United Nations Department of Safety and Security, is expected to have a final result by March.

Initial results from France, Germany and several other countries have shown that trained sniffer dogs are able to recognize people with COVID-19 infections, the statement said..

Sniffer dog could be an inexpensive, relatively simple and friendly alternative of screening methods currently used for slowing down COVID-19 transmission, said Dr Manuel Schibler, physician of the Infectious Diseases Department at HUG.

United States (January 24, 2021) The Denver Post:

The Heat will use coronavirus-sniffing dogs at AmericanAirlines Arena to screen fans who want to attend their games. They’ve been working on the plan for months, and the highly trained dogs have been in place for some games this season where the team has allowed a handful of guests — mostly friends and family of players and staff.

At Heat games, fans arriving for the game will be brought to a screening area and the detection dogs will walk past. If the dog keeps going, the fan is cleared; if the dog sits, that’s a sign its detect the virus and the fan will be denied entry.

Germany (February 3, 2021). Reuters:

“We did a study where we had dogs sniffing samples from COVID-positive patients and we can say that they have a 94% probability in our study … that they can sniff them out,” said Holger Volk, head of the veterinary clinic.

“So dogs can really sniff out people with infections and without infections, as well as asymptomatic and symptomatic COVID patients,” he added.

Stephan Weil, premier of Lower Saxony, the state of which Hanover is the capital, said he was impressed with the study and called for a feasibility tests before the sniffer dogs are put to use in everyday life, such as on people attending concerts.

Finland (January 1, 2020). United Nations:

Finland’s Helsinki-Vantaa airport has started using detection dogs to sniff out passengers possibly infected with the coronavirus. Dogs are providing a cheap, fast and effective alternative method of testing people for the virus. Around 100 travellers a day and 2200 per month have been queuing up for the test since the booth was set up in September. Testing has shown an accuracy level of nearly 100% even 5 days before actual symptoms appear.

These dogs are part of a pilot scheme project to keep the flying public safe and reduce the spread of COVID-19, alongside other measures. Currently, there are 6 dogs operating at Helsinki- Vantaa airport. The dogs are scheduled to continue screening arriving passengers at least until the end of the year, but according to the project leaders, the project is likely to continue until summer 2021.

Chile (December 23, 2020). Reuters:

The task of sniffing out passengers infected with COVID-19 at Chile’s Santiago international airport is going to the dogs.

A team of Golden Retrievers and Labradors sit when they smell the virus and get a treat. The canines sport green “biodetector” jackets with a red cross.

Passengers at an airport health checkpoint wipe their necks and wrists with gauze pads that are then put in glass containers and sent to the dogs to see if they detect COVID-19.

Chile’s Carabinero police trained the dogs and Inspector General Esteban Diaz said dogs have more than 3 million olfactory receptors, more than 50 times those of humans, so were uniquely placed to help fight the coronavirus.

Dubai (August 4, 2020). The Sun:

In a statement, Dubai’s Ministry of Interior said: “Data and studies showed that detection of presumed Covid-19 cases achieved approximately 92 per cent in overall accuracy.

“Figures indicate that dogs can quickly detect infected cases, help protect key sites, effectively deal with huge crowds and secure large events, airports, etc.”

The new sniffer dog scheme works by taking samples from passengers armpits before it is placed inside a container in an isolated room.

Specially-trained canines then sniff the samples through a funnel-like contraption.

If they detect coronavirus, the passenger is then directed to take the nasal PCR test.

The dogs never come in direct contact with the passengers.

This method has been used to detect several other diseases that can affect body odor such as cancer and malaria.

NASCAR and the Miami Heat moving into the implementation stage — it would be sports — is impressive. Also impressive is that this seems to be an organic phenomenon; I don’t see Fauci or Walensky on the teebee recommending sniffer dogs. Or WHO or CDC (I can’t find anything about sniffer dogs using their search function).[1]

Now let’s turn to some studies — even though NASCAR, at least, didn’t wait for them. (It may be that the pervasive use of sniffer dogs to detect drugs has prepared the public mind for the new purpose of detecting Covid, and so no action from our sclerotic Federal public health system is required. Perhaps that’s for the best.)

First, from Journal of Osteopathic Medicine, “Toward the use of medical scent detection dogs for COVID-19 screening.” This is a review of the literature, which is thin. From the Abstract:

In August 2020 and October 2020, the first author (T.D.) searched MEDLINE/PubMed, Cochrane Library, Google Scholar, and additional news articles using keyword phrases including “COVID scent dogs,” “COVID sniffer dogs,” and “COVID detection dog,” returning a total of 13 articles, nine of which were duplicates. Four remaining peer-reviewed studies dedicated to determining the feasibility and efficacy of detecting and screening individuals who may be infected by the COVID-19 virus with scent detection dogs were then examined. In this narrative review, the authors describe the methodologies and results of the remaining four studies, which demonstrated that the sensitivity, specificity, and overall success rates reported by the summarized scent detection studies are comparable to or better than the standard RT-PCR and antigen testing procedures, meaning that scent detection dogs can likely be effectively employed to nonintrusively screen and identify individuals infected with the COVID-19 virus in hospitals, senior care facilities, schools, universities, airports, and even large public gatherings for sporting events and concerts.

(I have to rely on the abstract’s conclusions, because so many journal articles are paywalled. The following two articles could be a subset of the four they found, or not.)

Second, from BMC Infectious Diseases, “Sniffer dogs as a screening/diagnostic tool for COVID-19: a proof of concept study“:

Sniffer dogs are able to detect certain chemical particles and are suggest to be capable of helping diagnose some medical conditions and complications, such as colorectal cancer, melanoma, bladder cancer, and even critical states such as hypoglycemia in diabetic patients. With the global spread of COVID-19 throughout the world and the need to have a real-time screening of the population, especially in crowded places, this study aimed to investigate the applicability of sniffer dogs to carry out such a task.

The sensitivity of this test was as high as 86% and its specificity was 92.9%. In addition, the positive and negative predictive values were 89.6 and 90.3%, respectively.

Conclusion: Dogs are capable of being trained to identify COVID-19 cases by sniffing their odour, so they can be used as a reliable tool in limited screening.

“Limited screening” is, I would think, fine, assuming the rate of false negatives is very low. Presumably those who the dogs detect can be moved aside and given a more accurate, if slower, test.

Third, a preprint from bioRxiv, “Use of Canine Olfactory Detection for Covid‐19 Testing Study On U.A.E. Trained Detection Dog Sensitivity“:

A total of 1368 trials were performed during validation, including 151 positive and 110 negative samples. 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 line‐ups, “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.

“Sensitivities increased after matching” translates to Federal standards and a professional association to me; systematize the training to bring as many dogs as possible to the highest level.

Turning now to cost-effectiveness, certainly professional sports teams and airports have answered that question, at their scale. Perhaps cost effectiveness is the problem. Returning to Finland’s example:

The pilot programme is costing approximately 300,000 euros which is significantly lower than for laboratory-based testing methods.

“PCR test cost approximately 4 million euros per month and sniffing less than 100,000 euros” says docent in clinical research of companion animals, Anna Hielm-Bjorkman of Helsinki University.

To look once more at the question the headline, contrast this approach, also proposed for sporting events and airports: “New York hospital launches COVID-19 saliva testing for those seeking to attend large events, fly internationally“:

Mount Sinai Hospital in New York is launching a COVID-19 saliva-testing program that could prove to be a game-changer for reopening large-scale events.

Holy moley. A game-changer! More:

The program was unveiled Monday and will offer “easy, effective and accurate COVID-19 test for the public” at four testing locations in Manhattan, according to Dr. David Reich, the hospital’s president. He told ABC News that the saliva testing is “equal in accuracy to nasal swabs.”

The test costs $139.50 and isn’t covered by insurance.

The test mainly will be used by those paying for the convenience of quickly being able to attend events such as professional sports or the theater, catering events through the state’s Excelsior Pass app program, or taking an international flight, Reich added.

New York Gov. Andrew Cuomo announced the launch of the Excelsior Pass program last month to confirm an individual’s recent negative COVID-19 test or proof of vaccination, data that could be used to help venues reopen in accordance with state Department of Health guidelines. Venues that announced they’ll use the app include Madison Square Garden in Manhattan and the Times Union Center in Albany.

Results from saliva tests should be available within 48 hours, but about 85% will be available within just 24 hours.

To take the test, patients can’t eat or drink anything, brush or floss their teeth or use mouthwash, or smoke or chew gum for one hour prior. The test also can be administered to young children, who may find it more comfortable than a nasal swab.

So, we have Option A (dogs): A test that’s quick, cheap, and accurate. And we have oPption B (Mount Sinai): A test that’s costly, not covered by insurance, having complex eligibility requirements (not eating or drinking), that’s slow. And requires an app. And is politically wired.[1]

Which do you think our health care system will choose: Option A (dogs), or Option B (Mount Sinai)? My money is on Option B, but perhaps I’m too pessimistic.

* * *

There is the issue of scale: To be fair to Mount Sinai, they can probably have their machines manufactured off shore, and all the rental collection over here and the app won’t have that much overhead. So perhaps the Mount Sinai solution is easier to scale in our financialized society, given the givens. On the other hand, there is already a sniffer dog industry, along with a police dog industry, a medical dog industry, and a seeing-eye dog industry, and there are a lot of dogs in the world. Somehow, I don’t think private equity is going to be able adapt factory farming techniques to training sniffer dogs, so scaling out sniffer dogs would probably require, besides Federal standards for accuracy, funding for a lot of local small businesses. That’s not a bad thing. Why not give small business sniffer dog projects a nice fat chunk of stimulus money?

NOTES

[1] Here is an article from The Atlantic. The content is exclusively cute pictures of sniffer dogs. I expected more.

[2] Probably gameable, too. How long before some clever person finds the mouthwash that defeats the test?