The Nose Knows: Dogs Are Being Trained to Detect the Coronavirus
Asher is eccentric and inquisitive. He loves an audience, likes keeping busy, and howls to be let through doors. He is a six-year-old working Cocker Spaniel, who, with five other furry colleagues, has now been trained to sniff body odor samples from humans to detect COVID-19 infections.
As the Delta variant and other new versions of the SARS-CoV-2 virus emerge, public health agencies are once again recommending masking while employers contemplate mandatory vaccination. While PCR tests remain the "gold standard" of COVID-19 tests, they can take hours to flag infections. To accelerate the process, scientists are turning to a new testing tool: sniffer dogs.
At the London School of Hygiene and Tropical Medicine (LSHTM), researchers deployed Asher and five other trained dogs to test sock samples from 200 asymptomatic, infected individuals and 200 healthy individuals. In May, they published the findings of the yearlong study in a preprint, concluding that dogs could identify COVID-19 infections with a high degree of accuracy – they could correctly identify a COVID-positive sample up to 94% of the time and a negative sample up to 92% of the time. The paper has yet to be peer-reviewed.
"Dogs can screen lots of people very quickly – 300 people per dog per hour. This means they could be used in places like airports or public venues like stadiums and maybe even workplaces," says James Logan, who heads the Department of Disease Control at LSHTM, adding that canines can also detect variants of SARS-CoV-2. "We included samples from two variants and the dogs could still detect them."
Detection dogs have been one of the most reliable biosensors for identifying the odor of human disease. According to Gemma Butlin, a spokesperson of Medical Detection Dogs, the UK-based charity that trained canines for the LSHTM study, the olfactory capabilities of dogs have been deployed to detect malaria, Parkinson's disease, different types of cancers, as well as pseudomonas, a type of bacteria known to cause infections in blood, lungs, eyes, and other parts of the human body.
COVID-19 has a distinctive smell — a result of chemicals known as volatile organic compounds released by infected body cells, which give off an odor "fingerprint."
"It's estimated that the percentage of a dog's brain devoted to analyzing odors is 40 times larger than that of a human," says Butlin. "Humans have around 5 million scent receptors dedicated to smell. Dogs have 350 million and can detect odors at parts per trillion. To put this into context, a dog can detect a teaspoon of sugar in a million gallons of water: two Olympic-sized pools full."
According to LSHTM scientists, COVID-19 has a distinctive smell — a result of chemicals known as volatile organic compounds released by infected body cells, which give off an odor "fingerprint." Other studies, too, have revealed that the SARS-CoV-2 virus has a distinct olfactory signature, detectable in the urine, saliva, and sweat of infected individuals. Humans can't smell the disease in these fluids, but dogs can.
"Our research shows that the smell associated with COVID-19 is at least partly due to small and volatile chemicals that are produced by the virus growing in the body or the immune response to the virus or both," said Steve Lindsay, a public health entomologist at Durham University, whose team collaborated with LSHTM for the study. He added, "There is also a further possibility that dogs can actually smell the virus, which is incredible given how small viruses are."
In April this year, researchers from the University of Pennsylvania and collaborators published a similar study in the scientific journal PLOS One, revealing that detection dogs could successfully discriminate between urine samples of infected and uninfected individuals. The accuracy rate of canines in this study was 96%. Similarly, last December, French scientists found that dogs were 76-100% effective at identifying individuals with COVID-19 when presented with sweat samples.
Grandjean Dominique, a professor at France's National Veterinary School of Alfort, who led the French study, said that the researchers used two types of dogs — search and rescue dogs, as they can sniff sweat, and explosive detection dogs, because they're often used at airports to find bomb ingredients. Dogs may very well be as good as PCR tests, said Dominique, but the goal, he added, is not to replace these tests with canines.
In France, the government gave the green light to train hundreds of disease detection dogs and deploy them in airports. "They will act as mass pre-test, and only people who are positive will undergo a PCR test to check their level of infection and the kind of variant," says Dominique. He thinks the dogs will be able to decrease the amount of PCR testing and potentially save money.
Since the accuracy rate for bio-detection dogs is fairly high, scientists think they could prove to be a quick diagnosis and mass screening tool, especially at ports, airports, train stations, stadiums, and public gatherings. Countries like Finland, Thailand, UAE, Italy, Chile, India, Australia, Pakistan, Saudi Arabia, Switzerland, and Mexico are already training and deploying canines for COVID-19 detection. The dogs are trained to sniff the area around a person, and if they find the odor of COVID-19 they will sit or stand back from an individual as a signal that they've identified an infection.
While bio-detection dogs seem promising for cheap, large-volume screening, many of the studies that have been performed to date have been small and in controlled environments. The big question is whether this approach work on people in crowded airports, not just samples of shirts and socks in a lab.
"The next step is 'real world' testing where they [canines] are placed in airports to screen people and see how they perform," says Anna Durbin, professor of international health at the John Hopkins Bloomberg School of Public Health. "Testing in real airports with lots of passengers and competing scents will need to be done."
According to Butlin of Medical Detection Dogs, scalability could be a challenge. However, scientists don't intend to have a dog in every waiting room, detecting COVID-19 or other diseases, she said.
"Dogs are the most reliable bio sensors on the planet and they have proven time and time again that they can detect diseases as accurately, if not more so, than current technological diagnostics," said Butlin. "We are learning from them all the time and what their noses know will one day enable the creation an 'E-nose' that does the same job – imagine a day when your mobile phone can tell you that you are unwell."
Time to visit your TikTok doc? The good and bad of doctors on social media
Rakhi Patel has carved a hobby out of reviewing pizza — her favorite food — on Instagram. In a nod to her preferred topping, she calls herself thepepperoniqueen. Photos and videos show her savoring slices from scores of pizzerias. In some of them, she’s wearing scrubs — her attire as an inpatient neurology physician associate at Tufts Medical Center in Boston.
“Depending on how you dress your pizza, it can be more nutritious,” said Patel, who suggests a thin crust, sugarless tomato sauce and vegetables galore as healthier alternatives. “There are no boundaries for a health care professional to enjoy pizza.”
Beyond that, “pizza fuels my mental health and makes me happy, especially when loaded with pepperoni,” she said. “If I’m going to be a pizza connoisseur, then I also need to take care of my physical health by ensuring that I get at least three days of exercise per week and eat nutritiously when I’m not eating pizza.”
She’s among an increasing number of health care professionals, including doctors and nurses, who maintain an active persona on social media, according to bioethics researchers. They share their hobbies and interests with people inside and outside the world of medicine, helping patients and the public become acquainted with the humans behind the scrubs or white coats. Other health care experts limit their posts to medical topics, while some opt for a combination of personal and professional commentaries. Depending on the posts, ethical issues may come into play.
“Health care professionals are quite prevalent on social media,” said Mercer Gary, a postdoctoral researcher at The Hastings Center, an independent bioethics research institute in Garrison, New York. “They’ve been posting on #medTwitter for many years, mainly to communicate with one another, but, of course, anyone can see the threads. Most recently, doctors and nurses have become a presence on TikTok.”
On social media, many health care providers perceive themselves to be “humanizing” their profession by coming across as more approachable — “reminding patients that providers are people and workers, as well as repositories of medical expertise,” Gary said. As a result, she noted that patients who are often intimidated by clinicians may feel comfortable enough to overcome barriers to scheduling health care appointments. The use of TikTok in particular may help doctors and nurses connect with younger followers.
When health care providers post on social media, they must bear in mind that they have legal and ethical duties to their patients, profession and society, said Elizabeth Levy, founder and director of Physicians for Justice.
While enduring three years of pandemic conditions, many health care professionals have struggled with burnout, exhaustion and moral distress. “Much health care provider content on social media seeks to expose the difficulties of the work,” Gary added. “TikTok and Instagram reels have shown health care providers crying after losing a patient or exhausted after a night shift in the emergency department.”
A study conducted in Beijing, China and published last year found that TikTok is the world’s most rapidly growing video application, amassing 1.6 billion users in 2021. “More and more patients are searching for information on genitourinary cancers via TikTok,” the study’s authors wrote in Frontiers in Oncology, referring to cancers of the urinary tracts and male reproductive organs. Among the 61 sample videos examined by the researchers, health care practitioners contributed the content in 29, or 47 percent, of them. Yet, 22 posts, 36 percent, were misinformative, mostly due to outdated information.
More than half of the videos offered good content on disease symptoms and examinations. The authors concluded that “most videos on genitourinary cancers on TikTok are of poor to medium quality and reliability. However, videos posted by media agencies enjoyed great public attention and interaction. Medical practitioners could improve the video quality by cooperating with media agencies and avoiding unexplained terminologies.”
When health care providers post on social media, they must bear in mind that they have legal and ethical duties to their patients, profession and society, said Elizabeth Levy, founder and director of Physicians for Justice in Irvine, Calif., a nonprofit network of volunteer physicians partnering with public interest lawyers to address the social determinants of health.
“Providers are also responsible for understanding the mechanics of their posts,” such as who can see these messages and how long they stay up, Levy said. As a starting point for figuring what’s acceptable, providers could look at social media guidelines put out by their professional associations. Even beyond that, though, they must exercise prudent judgment. “As social media continues to evolve, providers will also need to stay updated with the changing risks and benefits of participation.”
Patients often research their providers online, so finding them on social media can help inform about values and approaches to care, said M. Sara Rosenthal, a professor and founding director of the program for bioethics and chair of the hospital ethics committee at the University of Kentucky College of Medicine.
Health care providers’ posts on social media also could promote patient education. They can advance informed consent and help patients navigate the risks and benefits of various treatments or preventive options. However, providers could violate ethical principles if they espouse “harmful, risky or questionable therapies or medical advice that is contrary to clinical practice guidelines or accepted standards of care,” Rosenthal said.
Inappropriate self-disclosure also can affect a provider’s reputation, said Kelly Michelson, a professor of pediatrics and director of the Center for Bioethics and Medical Humanities at Northwestern University’s Feinberg School of Medicine. A clinician’s obligations to professionalism extend beyond those moments when they are directly taking care of their patients, she said. “Many experts recommend against clinicians ‘friending’ patients or the families on social media because it blurs the patient-clinician boundary.”
Meanwhile, clinicians need to adhere closely to confidentiality. In sharing a patient’s case online for educational purposes, safeguarding identity becomes paramount. Removing names and changing minor details is insufficient, Michelson said.
“The patient-clinician relationship is sacred, and it can only be effective if patients have 100 percent confidence that all that happens with their clinician is kept in the strictest of confidence,” she said, adding that health care providers also should avoid obtaining information about their patients from social media because it can lead to bias and risk jeopardizing objectivity.
Academic clinicians can use social media as a recruitment tool to expand the pool of research participants for their studies, Michelson said. Because the majority of clinical research is conducted at academic medical centers, large segments of the population are excluded. “This affects the quality of the data and knowledge we gain from research,” she said.
Don S. Dizon, a professor of medicine and surgery at the Warren Alpert Medical School of Brown University in Providence, Rhode Island, uses LinkedIn and Doximity, as well as Twitter, Instagram, TikTok, Facebook, and most recently, YouTube and Post. He’s on Twitter nearly every day, where he interacts with the oncology community and his medical colleagues.
Also, he said, “I really like Instagram. It’s where you will see a hybrid of who I am professionally and personally. I’ve become comfortable sharing both up to a limit, but where else can I combine my appreciation of clothes with my professional life?” On that site, he’s seen sporting shirts with polka dots or stripes and an occasional bow-tie. He also posts photos of his cats.
Don S. Dizon, a professor of medicine and surgery at Brown, started using TikTok several years ago, telling medical stories in short-form videos.
Don S. Dizon
Dizon started using TikTok several years ago, telling medical stories in short-form videos. He may talk about an inspirational patient, his views on end-of-life care and death, or memories of people who have passed. But he is careful not to divulge any details that would identify anyone.
Recently, some people have become his patients after viewing his content on social media or on the Internet in general, which he clearly states isn’t a forum for medical advice. “In both situations, they are so much more relaxed when we meet, because it’s as if they have a sense of who I am as a person,” Dizon said. “I think that has helped so much in talking through a cancer diagnosis and a treatment plan, and yes, even discussions about prognosis.”
He also posts about equity and diversity. “I have found myself more likely to repost or react to issues that are inherently political, including racism, homophobia, transphobia and lack-of-access issues, because medicine is not isolated from society, and I truly believe that medicine is a social justice issue,” said Dizon, who is vice chair of diversity, equity, inclusion and professional integrity at the SWOG Cancer Research Network.
Through it all, Dizon likes “to break through the notion of doctor as infallible and all-knowing, the doctor as deity,” he said. “Humanizing what I do, especially in oncology, is something that challenges me on social media, and I appreciate the opportunities to do it on TikTok.”
Could this habit related to eating slow down rates of aging?
Last Thursday, scientists at Columbia University published a new study finding that cutting down on calories could lead to longer, healthier lives. In the phase 2 trial, 220 healthy people without obesity dropped their calories significantly and, at least according to one test, their rate of biological aging slowed by 2 to 3 percent in over a couple of years. Small though that may seem, the researchers estimate that it would translate into a decline of about 10 percent in the risk of death as people get older. That's basically the same as quitting smoking.
Previous research has shown that restricting calories results in longer lives for mice, worms and flies. This research is unique because it applies those findings to people. It was published in Nature Aging.
But what did the researchers actually show? Why did two other tests indicate that the biological age of the research participants didn't budge? Does the new paper point to anything people should be doing for more years of healthy living? Spoiler alert: Maybe, but don't try anything before talking with a medical expert about it. I had the chance to chat with someone with inside knowledge of the research -- Dr. Evan Hadley, director of the National Institute of Aging's Division of Geriatrics and Clinical Gerontology, which funded the study. Dr. Hadley describes how the research participants went about reducing their calories, as well as the risks and benefits involved. He also explains the "aging clock" used to measure the benefits.
Evan Hadley, Director of the Division of Geriatrics and Clinical Gerontology at the National Institute of Aging
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