The sudden inability to smell and taste that comes with COVID is startling and difficult to describe. I was lucky to experience it only for a few days.
Anosmia is the partial or total loss of the ability to smell, which vanquishes most of the sense of taste, too. The COVID version is more profound than the familiar dulling of the sense from the mucus of a common cold. And it has a different origin.
The odd part of COVID anosmia is that the virus alters gene expression in nerve cells in the nose – even though the virus can't actually enter nerve cells (neurons). Then the temporarily crippled cells can't signal the brain that the person is inhaling near the seashore or passing a garbage dump. Understanding the basis of the secondhand assault may clarify other puzzling effects of the changeling coronavirus – perhaps even long COVID.
Clever experiments recently revealed how COVID anosmia happens. Benjamin R. tenOever and colleagues from the NYU Grossman School of Medicine and Columbia University report their work using golden hamsters and the noses of human corpses in Cell.
First, a closer look at how the sense of smell works.
To continue reading, go to my DNA Science blog at Public Library of Science, where this post first appeared.