Using Candy To Sniff Out Probable Cases Of COVID-19
Susan Travers, PhD,
Part of Research Team Developing Method to Screen for Taste and Smell Loss
Scientists have proposed that using a cheap and simple product – hard candy – to screen for the loss of taste and smell in populations at risk for COVID-19 exposure may help detect probable positive cases in otherwise asymptomatic people.
The Ohio State University research team received $305,000 in National Institutes of Health funding in a competitive bid to develop easy-to-deploy strategies that can identify people who are potentially infected with SARS-CoV-2.
While symptoms like fever, chills, a cough and body aches vary widely among COVID-19 patients, an estimated 86% of people who test positive report a loss of smell, “which makes it a much better predictor, especially if it’s sudden loss,” said project co-leader Christopher Simons, PhD, associate professor of food science and technology at Ohio State.
Eight flavors of hard candies that are uniform in color have been manufactured for the study. Asking people to identify flavors by tasting the candies allows for sophisticated assessment of the function of two sensory systems – taste and smell – by which we can tell what we’re eating, Simons said.
Plus, the sweet treat is hard to resist as a scientific screening tool.
“Who doesn’t like candy? It’s an ideal stimulus because for this to work, people have to want to do it,” Dr. Simons said.
Simons’ lab in the College of Food, Agricultural and Environmental Sciences focuses on understanding the neural and physiological underpinnings of how we perceive food. The research team also includes taste biologist Susan Travers, PhD, professor of the Division of Biosciences in the College of Dentistry, and Kai Zhao, PhD, associate professor of Otolaryngology in the College of Medicine, who specializes in olfaction – the sense of smell.
The new funding is a competitive revision to one of Dr. Travers' existing NIH grants. "After working on the basic neural circuitry for taste in animal models for many years, I am thrilled to have the opportunity to team up with my colleagues, Drs. Simons and Zhao, experts in human taste and smell, to help develop a test useful for the Covid-19 crisis," Dr. Travers said. "In fact, a fast, reliable, and agreeable tool like the 'candy test' has potential to be applied to other clinical conditions that affect the chemical senses, such as Alzheimer's disease."
If this method is adopted as a screening strategy, it would complement existing tools for this purpose: a scratch-and-sniff card for smell and/or a one-time evaluation of the bitter medication quinine for taste, both of which are more expensive than candy (less than 5 cents for a piece of candy versus more than 50 cents per scratch-and-sniff card).
The first phase of the Ohio State project has involved validating the use of candy against those established methods. Preliminary assessments have been promising, though the pace of the work has decreased as the team continues to seek eligible participants.
Long-term tracking occurs in the project's second phase, for which recruitment is just beginning. The team plans to follow about 2,800 people for 90 days. Ohio State students, staff, and faculty are a key recruitment target for the study.
Participants are asked to consume a piece of hard candy once per day and log into a survey app developed by Dr. Zhao to report what they smell and taste - not only by identifying the flavor, but also rating its intensity. If they report a sudden drop in either sense, they receive a message that they should quarantine and get a COVID-19 test.
"With our assessment, you unwrap the candy, and pop it into your mouth to identify the candy's flavor and rate how strong it is, which is the smell component. You also assess sweetness and sourness, which is the taste component. It allows us to tackle three different aspects of flavor perception," Dr. Simons said.
Though the researchers have hypothesized that both the smell and taste pathways are affected by SARS-CoV-2, their first order of business is providing what the NIH is looking for: "a fairly simple, inexpensive and deployable technology to support public health," Simons said.