New VCU Study suggests smell and taste loss no longer COVID-19 infection indicator

RICHMOND, Va. (WRIC) — A new study led by researchers at Virginia Commonwealth University’s (VCU) School of Medicine suggests smell and taste loss are no longer reliable indicators of a COVID-19 infection.

The study revealed the risk of losing one’s sense of smell and taste is as low as 6% with recent Omicron variant waves, compared to 50% of people who would have experienced chemo-sensory losses, or the loss of the sense of taste and smell, in the initial stages of the pandemic.

Researchers used the National COVID Cohort Collaborative database — a collection of secure and de-identified clinical data of COVID-19 across the nation — to identify patients with and without chemo-sensory losses, along with CoVariants, to determine peak time intervals of when different viral sub-variants of COVID-19 were surging.

The time period studied began from the period of “Untyped” variants (before different mutations of the COVID-19 virus were typed or identified) to variants that would follow: “Untyped,” Alpha, Delta, Omicron K, Omicron L, Omicron C, Omicron B.

“We found rates of smell loss were down to about 6%-7% of what they were initially,” said Dr. Evan Reiter, MD, lead author of the study and professor in the Department of Otolaryngology at VCU, “6%-7% of that baseline – and the baseline if we just say that’s 50%, we’re estimating somewhere in the neighborhood of maybe 3%-5% of people losing their sense of smell with COVID infection now.”

When asked why rates of chemo-sensory loss among people infected with COVID-19 may have decreased, Dr. Reiter said there are multiple factors.

“The variants are a little bit less likely to penetrate the mucous blanket inside the nose, so they may be unable to penetrate that to get to the old factory receptors which are high up in the nasal cavity to access the nerves sense of smell,” he said.

Immunity also plays a factor, as Dr. Reiter added that, with vaccinations and previous infections, there is now a greater amount of acquired immunity than when the pandemic began.

Being unable to taste of smell can pose a great inconvenience to one’s daily living, but there are also health risks, including energy and weight loss, as well as malnutrition.

“In some cases, either from the way the virus damages the receptors of sense of smell or the way they come back, if they come back—partially some people get a pretty dramatic distortion of their sense of smell and taste,” Reiter said, “If they’re sitting down and eating something—they’re having a cheeseburger, it no longer smells and tastes like a cheeseburger, now it smells and tastes like garbage.”

Food aversions aren’t the only issues chemo-sensory loss pose, Reiter adds safety is also of a concern. For example, someone without a sense of taste or smell may not be aware if there is a fire nearby or notice if the food they are eating has spoiled.

VCU researchers hope the public understands the COVID-19 virus has now changed and past indicators are not as reliable as they were to differentiate whether one has contracted the virus, a common cold, or any other respiratory illness.

Because of this, Reiter suggests increasing testing and continuing common practices which prevent infection, such as hand-washing and isolation.

“I think depending on the severity and their work, and possibility of exposing other people, it might be worthwhile to go back to that practice a little bit more than people are doing now because you can’t really differentiate COVID from a non-COVID infection just based on those symptoms,” he said.