Lost your sense of smell? That could be worrying. A number of studies have suggested that a sudden loss of the ability to smell may be a symptom of COVID-19, the disease caused by the novel coronavirus, even when patients experience no other symptoms.
Based on this growing evidence, Israeli scientists from the Weizmann Institute of Science have teamed up with the Wolfson Medical Center to develop SmellTracker, an online platform that enables self-monitoring of an individual’s sense of smell to detect early signs of COVID-19, the Weizmann Institute announced last week.
The platform is based on an algorithm developed in the laboratory of Prof. Noam Sobel at the Weizmann Institute’s Department of Neurobiology. The researchers from that lab developed a mathematical model known as an
“olfactory fingerprint” to accurately characterizes a person’s sense of smell, which the researchers have said is unique to each person.
SmellTracker, available in nine languages, asks users to select five common household items (spices, vinegar, toothpaste, peanut butter, etc.) and rate them according to their own odor perception based on pre-formulated questions. The smell test only takes about five minutes but it’s enough time to be an early indication of COVID-19 if there are sudden changes in odor perception. Researchers report that the new online tool has already successfully identified potential COVID-19 cases which were late confirmed, Weizmann Institute said.
While researchers emphasize that the SmellTracker is not the same as an official medical diagnosis, they hope that the tool will at the very least help them characterize the unique olfactory fingerprint that could lead to early detection until more data is collected.
Different from the common cold
The Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) have said symptoms like fever, coughing, and shortness of breath, appearing between two days and two weeks after exposure to the virus, are all potential signs of coronavirus. Doctors have recently added loss of smell and taste as two more potential symptoms that could show up on their own, science news website Live Science reported last month.
While it wasn’t a common symptom in the city of Wuhan, China, where the coronavirus outbreak first began, the Weizmann Institute reported that preliminary studies conducted in several countries, including Israel and Iran, show that this symptom appears in about 60 percent of patients.
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In South Korea, 30 percent of patients who tested positive have had a loss of sense of smell as a major symptom in otherwise mild cases, according to tech, science, and culture website CNet. In Germany, at least two in three confirmed COVID-19 patients have anosmia, according to a joint statement from Claire Hopkins of the British Rhinological Society and Nirmal Kumar, president of ENT UK, a professional body representing ear, nose and throat surgeons.
It’s not just the loss of sense of smell one might experience with a common cold, either. Prof. Sobel said with COVID-19, what seems to be emerging is that “people lose their sense of smell quite rapidly with no restriction on nasal airflow,” he told Israeli global television news channel i24.
“That is, they can sniff, they’re not blocked. They don’t have a stuffy nose. But they just cannot smell a thing,” he explained.
Prof. Sobel’s lab is also distributing “scratch and sniff” kits based on adapted sensors among confirmed coronavirus patients “in an attempt to map their sense of smell,” the Weizmann Institute reported. The sensors monitor changes in patients’ airflow which can signal a deterioration.
Sobel also said his team has created a tiny wearable that weighs six grams and transmits data via Bluetooth. The wearable sensor is ready for use by coronavirus patients, but is awaiting regulatory approval, Sobel said.
SmellTracker was launched with backing from the Ministry of Defense. It will be officially promoted outside of Israel in countries like Sweden and France.