Want to know why you lost your sense of smell after a COVID-19 infection? A small new study may have the answer.
The research, published Wednesday in Science Translational Medicine, found it has to do with inflammation in the olfactory system, which includes the nose and the nasal cavities. That’s where our ability to smell is located.
It has long been a mystery why some people who get COVID lose their sense of taste or smell. In some cases, people have lost their sense of smell for years after recovering from COVID. Physicians refer to this as “olfactory dysfunction.”
Patients who reported the loss of smell have fewer olfactory sensory neurons than those who could smell normally, based on an analysis of 24 biopsies of nasal tissue in people who recovered from COVID. Nine of those samples came from patients with long-term loss of smell.
“We think the reduction of sensory neurons is almost definitely related to the inflammation,” Dr. Brad Goldstein, one of the study’s co-authors and a sinus surgeon at Duke University in Durham, N.C., told The Wall Street Journal.
T cell–mediated inflammation can persist in the olfactory system long after infection, the study found. T-cells, like antibodies, are part of the body’s immune response to a COVID infection.
Another study, published earlier this month in PLOS One and conducted by researchers at Columbia University, had a similar finding, citing antibodies as the reason for the loss of smell. “Our results suggest the presence of a robust anti-Spike IgG response in individuals experiencing smell and taste loss during COVID-19 infection,” those researchers concluded.
COVID news to know:
• Stop testing patients for COVID before surgery. That’s the new recommendation from the Healthcare Epidemiology of America, which says that universal screening of asymptomatic patients before a hospital visit has an “unclear benefit.”
• Hospital in China expects millions of new COVID cases. A hospital in Shanghai reportedly told its workers to prepare for half of the city’s 25 million residents to get sick by the end of next week, calling it a “tragic battle” with COVID, according to Reuters.
• India is preparing for a COVID surge. The country’s health minister told people to start wearing masks again and get their boosters, according to the BBC. Cases in India remain low; however, the country is paying close attention to the surge in infections in China.
• A monoclonal antibody gets full FDA approval. The Food and Drug Administration granted full approval to Roche Holding’s
Actemra, its rheumatoid arthritis treatment, for adults who have been hospitalized with severe COVID. The monoclonal antibody, which has treated more than 1 million people, first received emergency authorization in mid-2021.
• COVID infections in the U.S. are still rising. The seven-day average of daily new COVID cases surged to a 15-week high of 67,491 on Wednesday, according to a New York Times tracker, the most since Sept. 8. Three states have seen cases more than double in the past two weeks, with Michigan jumping 378%, Georgia growing 127%, and Rhode Island rising 105%. The number of COVID-related hospitalizations has increased 8% in two weeks to 40,129, and the daily average for deaths was 413, up 21% in two weeks.