Nov. 19, 2021 -- A new study says 700,000 to 1.6 million people in the United States who got COVID-19 may have lost their sense of smell for 6 months or longer.
That’s the conclusion of researchers at the Washington University in St. Louis who started the study after a growing number of patients reported their smell and taste months after they got over COVID.
“In the last couple of months, my colleagues and I noted a dramatic increase in the number of patients seeking medical attention for olfactory dysfunction.” Jay Piccirillo, the study author and an otolaryngologist at Washington University, told Gizmodo.
The researchers started by looking at the number of daily new cases of coronavirus reported by the COVID Tracking Project between Jan.13, 2020, and March 7, 2021, according to a research letter about the study published in JAMAOtolaryngology – Head & Neck Surgery.
They worked in the incidence of acute COVID olfactory dysfunction (OD) at 52.7% (based on a recent meta-analysis) and the recovery rate from OD at 95.3% (based on a prospective study).
“This analysis of new daily cases of COVID-19, acute incidence of OD, and rates of recovery suggest that more than 700 000, and possibly as many as 1.6 million, U.S. individuals experience COD (chronic olfactory dysfunction) because of SARS-CoV-2,” the study said.
These numbers include people who reported parosmia, or a distorted sense of smell that can make a normally pleasant smell, like that of fresh fruit, smell bad or rotten. Researchers cautioned that their numbers may well be an undercount as the pandemic is not over.
Other conditions besides COVID can cause COD, the study says. Adding 700,000 to 1.6 million COVID-related cases of COD represents a 5.3% to 12% relative increase in the total number of people with COD, they said.
And long-term loss of smell caused by COVID will hit the younger age groups harder, the authors said.
"COVID-19 affects a younger demographic group than other causes of olfactory dysfunction," the study said. "Thus, the lifelong burden of olfactory dysfunction will be much greater for the COVID-19 cohort than for patients in the older age groups."