Between 700,000 and 1.6 million people in the US who had COVID-19 had a loss or change in smell that lasted for more than six months, researchers estimate.
By Korin Miller
A lost sense of smell was one of the first known symptoms of COVID-19. And since the pandemic first began, many people have talked about the frustration of losing their ability to smell after contracting the virus. While not everyone who’s had COVID develops this symptom, plenty do—and the loss of smell can linger for well after someone has recovered from the virus itself.
A new research letter published in the journal JAMA Otolaryngology-Head & Neck Surgery on November 18 estimates that somewhere between 700,000 to 1.6 million people in the US who had COVID-19 had a loss of smell—or a change in their sense of smell—that lasted for more than six months. And according to the researchers, this is likely an underestimate.
Because of the large amount of people affected by the sense change and its potential implications on health and well-being, the researchers are calling the long-term loss of smell—which medically is known as chronic olfactory dysfunction, or COD—that’s associated with COVID a “public health concern.”
The study looked at the number of new daily COVID-19 cases in the US from the COVID Tracking Project, specifically analyzing cases that were reported between January 13, 2020, and March 7, 2021. The researchers compared those infection rates with data from two studies that showed that 52.7% of people with COVID-19 had lost their sense of smell, known as olfactory dysfunction (OD), but that 95.3% had regained it. Using the infection rates as well as the percentages from the two studies, the researchers were able to estimate how many people with COVID developed OD but never gained back their sense of smell—in other words, how many people developed COD.
“These data suggest an emerging public health concern of OD and the urgent need for research that focuses on treating COVID-19 COD,” the researchers wrote.
But why were researchers even studying the rate of OD among those who had COVID in the first place? That’s because they “noted a large number of patients seeking attention for COVID-associated anosmia [which is the total or partial loss of smell] that persisted for more than three months,” study co-author Jay F. Piccirillo, MD, professor and vice chair for research in the Department of Otolaryngology – Head and Neck Surgery at the Washington University School of Medicine, tells Health.
Before the pandemic, 13.3 million adults aged 40 years and up had OD or COD. That number has significantly increased during the pandemic and likely will continue to rise, Dr. Piccirillo says. And that uptick is a concern for him and his colleagues.