Millions still without sense of smell or taste after Covid-19
Research shows 5% of people who had Covid are dealing with long-lasting loss of smell or taste, a shift one expert said could be considered “a new public health crisis.”
Millions of people are believed to still be suffering from the loss of smell or taste after bouts of Covid-19.
Millions of people are believed to still be suffering from the loss of smell or taste after bouts of Covid-19.
Still struggling with your sense of smell after a bout with Covid-19? You’re far from alone.
About 5% of patients with confirmed cases of Covid-19 — some 27 million people worldwide — are estimated to have suffered a long-lasting loss of smell or taste, a new analysis suggests.
In the analysis published Wednesday in The BMJ (the peer-reviewed medical journal of the British Medical Association), researchers evaluated 18 previous studies of smell and taste loss across several continents and in varying demographic groups. About three quarters of those affected by loss of taste or smell regained those senses within 30 days.
Rates of recovery improved over time, but about 5% of people reported “persistent dysfunction” six months after their infection with Covid-19.
The analysis suggests loss of smell and taste could be a prolonged concern that requires more research and health resources for patients struggling with long-term symptoms.
Losing smell has been linked to higher death rates in older adults and has been shown to have major impacts on people’s emotional and psychological well-being, said Dr. Zara Patel, a rhinologist at Stanford University who was not involved in The BMJ research.
“Having these now millions more people worldwide with decreased ability to smell — that may simply be a new public health crisis,” Patel said.
Loss of smell was one of the most distinct markers of Covid-19 in the pandemic’s beginning days.
“You could track the pandemic across the globe” by analyzing Google searches about smell loss, Patel said.
The BMJ analysis gives a broad review of smell studies across the world and over time. Data from nearly 3,700 patients was included in the analysis.
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Studies from North America, Europe and Asia were all included in the analysis, which noted that women were less likely to regain their senses of smell and taste than men. Patients with greater nasal congestion were less likely to recover, also.
The analysis showed steady increases in the proportion of patients who recovered their sense of smell over time. After 30 days, about 74% of patients had recovered it; after 90 days that number was up to 90%. After six months, about 96% of patients said they were able to smell again.
Scientists are beginning to grasp how Covid-19 affects the smelling function.
The coronavirus often causes swelling in the olfactory cleft, that is, the passages in the upper part of the nasal cavity where humans perceive the sense of smell and process flavor beyond basic tastes like sour or bitter.
Researchers think the virus does not initially infect the olfactory neurons but instead latches on to support cells, which help the neurons provide a signaling pathway.
Patients who suffered smell loss after Covid-19 make up a unique subset, said Dr. Aria Jafari, a rhinologist at the UW Medicine Sinus Center in Seattle, who was not involved in the new analysis. “They tend to get better and kind of quickly, which makes sense based on the cells that are affected.”
Jafari said about half of his patients deprived from the sense of smell likely had Covid-19 at some point. Many experienced dramatic impacts on their well-being because of the loss.
“They tend to be distraught about the loss of sense of smell. It’s such an important part of our every day and what makes us human,” Jafari said, adding that he’s treated a professional chef, a chocolatier and others whose livelihoods depend on their ability to determine smell and flavor. “The most common thing I hear is that it leads to social isolation and feeling disconnected from the world and society as they know it. And that can be really bothersome.”
