By Prof. Noam Sobel
Along with fever, cough and shortness of breath, many coronavirus (COVID-19) patients report a temporary loss of their sense of smell. This olfactory loss appears to be significantly greater in COVID-19 patients compared to the normal loss that accompanies the common cold, orless commonly, in those suffering from the regular flu.
Based on the data that has already been collected, Weizmann Institute scientists, in collaboration with researchers and physicians in the Edith Wolfson Medical Center, developed SmellTracker – an online platform that enables self-monitoring of one’s sense of smell – as this seems to be an early sign of the disease, or one that appears in those who are otherwise asymptomatic.
Prof. Noam Sobel’s laboratory in the Weizmann Institute’s Department of Neurobiology specializes in olfactory research. The researchers in his lab had previously developed a mathematical model that characterizes an individual’s unique sense of smell – a kind of personal “olfactory fingerprint.” SmellTrackeruses this algorithm to present users with an online scent test,guiding them through the process of mapping their sense of smell using five scents found in theirhomes (spices, vinegar, toothpaste, various scent extracts, peanut butter, etc.).
The odor test lasts about five minutes and it enables users to be aware of any sudden changes in odor perception that may be an early indication of the onset of coronavirus. The researchers report that the tool they developed has already successfully identified potential coronavirus cases, which were later confirmed. Aside from personal monitoring, as more data is collected, the researchers think they will even be able to characterize a unique olfactory fingerprint for the early detection of COVID-19.
Eight Strains of Coronavirus
Olfactory loss was not commonly reported in the city of Wuhan, China, where the first coronavirus outbreak took hold. Nevertheless, preliminary studies conducted in several countries, including Israel and Iran, show that this symptom appears in about 60% of patients. Scientists estimate that there are currently eight active strains of the virus; Sobel’s team members suggests that olfactory loss might be a symptom of only some of the strains. If this turns out to be true, the SmellTracker will be able to map the various strains geographically.
Besides SmellTracker, Sobel’s lab is distributing “scratch and smell” kits among confirmed coronavirus patients in an attempt to map their sense of smell, accompanied by a more detailed questionnaire.
The venture, which was launched with backing from the Ministry of Defense, will be officially promoted in the coming days in Sweden, France and other countries. The scent test is currently available in English, Hebrew and Arabic, and is also expected to be available in Swedish, French, Japanese, Spanish, German and Persian.
Prof. Noam Sobel is head of the Azrieli National Institute for Human Brain Imaging and Research; his research is supported by the Norman and Helen Asher Center for Human Brain Imaging; the Nadia Jaglom Laboratory for the Research in the Neurobiology of Olfaction.