The high cost of slow adoption

A scholarly paper published in September 2021 in PLOS ONE titled “Highly Sensitive Scent-Detection of COVID-19 Patients In Vivo by Trained Dogs” (Omar Vesga et al) starts with this sentence:

“Timely and accurate diagnostics are essential to fight the COVID-19 pandemic, but no test satisfies both conditions. … The only effective measure to ameliorate the impact of the COVID-19 pandemic is early and accurate identification of people infected with SARS-CoV-2.”

…and ends with this:

“These data suggest that well-trained dogs can be extremely helpful to guide societies through a safe re-opening of the economy and educational systems, while offering an efficient way to stop transmission. With improved training methods, canines could, in the near future, provide a sensitive and effective method to detect infectious diseases in a matter of seconds. “

The researchers demonstrate that canine scent-detection of COVID-19 is highly accurate when the dog is able to sniff the human subject directly (in vivo), detecting more than 99% of infected individuals, whether the person was pre-symptomatic (too early in the infection to show symptoms), asymptomatic or displaying symptoms.

Our current standard diagnostic test is the rRT-PCR, which can be expensive and difficult to access; it lacks sensitivity during the first 5 days after exposure. The antigen tests, which are cheap and easily accessible, are good at detecting COVID in the first 7 days but lose sensitivity after that. Scent detection has none of these drawbacks: it’s fast, reliable, cost-effective and detects any infection regardless of the time since infection. Its only real drawback is that it’s not a medical standard.

The authors again:

“Medical diagnosis by trained canines triggers hope and enthusiasm among journalists, but it receives no attention from practicing clinicians, who rely exclusively on semiology and sophisticated instruments to determine what afflicts their patients. The use of scent-specialized dogs to detect specific conditions has been published, but most are anecdotal reports instead of formal protocols designed to validate a diagnostic test for clinical use. However, a few studies have demonstrated that with appropriate training and strict adherence to the scientific method, it is possible to obtain consistent results. Recently, a comprehensive method was published to validate canine diagnosis of the plant pathogens Candidatus Liberibacter asiaticus and Xanthomonas citri pv. citri, demonstrating that detection of infected citrus trees by dogs was superior to quantitative PCR.”

James Garfield, the 20th President of the United States, was shot by an assassin on July 2, 1881 and died weeks later on September 18th. Candice Millard wrote a biography of Garfield called Destiny of the Republic: A Tale of Madness, Medicine and the Murder of a President; it’s a fascinating book, well written and thoroughly engaging.

Garfield was shot in a rail station. The shots themselves weren’t fatal; they missed the spinal column and vital organs. The first doctor on the scene gave Garfield an ounce of brandy and aromatic spirits of ammonia to keep him conscious.

What Townsend did next was something that Joseph Lister, despite years spent traveling the world, proving the source of infection and pleading with physicians to sterilize their hands and instruments, had been unable to prevent. As the president lay on the train station floor, one of the most germ-infested environments imaginable, Townsend inserted an unsterilized finger into the wound in his back, causing a small hemorrhage and almost certainly intruding an infection that was far more lethal than Guiteau’s bullet.”

Candice Millard, ‘Destiny of the Republic’

If Garfield had not been treated at all, he likely would have survived the shooting. Instead, he was treated by a succession of doctors, all hoping to provide the best care for the President of the United States.

Although five years had passed since Lister presented his case to the Medical Congress at the Centennial exhibition, many American doctors still dismissed not just his discovery, but even Louis Pasteur’s. They found the notion of ‘invisible germs’ to be ridiculous, and they refused to even consider the idea that they could be the cause of so much disease and death.


Not only did many American doctors not believe in germs, they took pride in the particular brand of filth that defined their profession. They spoke fondly of the ‘good old surgical stink’ that pervaded their hospitals and operating rooms, and they resisted making too many concessions even to basic hygiene. Many surgeons walked directly from the street to the operating room without bothering to change their clothes. Those who did shrug on a laboratory coat, however were an even greater danger to their patients. They looped strands of silk sutures through their buttonholes for easy access during surgery, and they refused to change or even wash their coats. They believed that the thicker the layers of dried blood and pus, black and crumbling as they bent over their patients, the greater the tribute to their years of experience.


In the midst of the arrogance, distrust and misunderstanding that characterized the American medical establishment’s attitude toward Lister’s theories, there was a small but growing bastion of doctors who understood the importance of practicing antisepsis, not halfheartedly but precisely. A young surgeon in New York would later write that he and his colleagues had watched with helpless horror the progress of Garfield’s medical care. The president’s life might have been spared, he wrote with disgust, ‘had the physician in charge abstained from probing Garfield’s wound while he lay on a filthy mattress spread on the floor of a railroad station.’

Candice Millard, ‘Destiny of the Republic’

After weeks of suffering, Garfield eventually died of an infection introduced into his body by a physician who was aware of published, proven research on antisepsis but chose to ignore it.

The first antiseptic surgery was performed by Joseph Lister in August 1865. However, adoption was slow: as Atul Gawande notes in the article “Slow Ideas” (The New Yorker, July 12, 2013):

“It was a generation before Lister’s recommendations became routine and the next steps were taken toward the modern standard of asepsis—that is, entirely excluding germs from the surgical field, using heat-sterilized instruments and surgical teams clad in sterile gowns and gloves.”

Atul Gawande, “Slow Ideas”, The New Yorker

Why the slow adoption? Comparing it to the much quicker adoption of anesthesiology, Dr. Gawande notes the headwinds facing Lister and his proponents: the invisibility (to the unaided eye) of germs, and the fact that the new procedures burdened rather than benefited the doctor personally. It was simply easier to ignore Lister’s ideas, and those that did felt no direct consequences.

Eventually, the medical profession adopted the idea of scientific professionalism (white coats and sterile instruments and environments) and modernized their practices. During those decades, how many lives were lost needlessly?

As a new COVID variant starts to spread across a world that appears helpless to stop this pandemic, disavowing a timely and accurate diagnostic method because it doesn’t align with prevailing medical beliefs seems little different from the Victorian era in which physicians scoffed at germ theory.

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