Smell in the time of Covid-19 pandemic!

Researchers estimate that about four out of five Covid-19 patients suffer a partial or total loss of smell, a condition known as anosmia. Many have no other symptoms. And no, it’s got nothing to do with stuffy noses; it’s all about the havoc the coronavirus wreaks on our nervous systems.
Many patients recover their olfaction quickly. Others smell less than they did before (hyposmia) or scent every odor wrong (parosmia). A spouse suddenly smells like a stranger and sewage like coffee. And some people never regain any olfaction. Worldwide, they must already number in the millions.
Smell, as much of the world is discovering in the pandemic, has long been our most underrated sense. We generally appreciate it less than the other four. Perhaps that’s why we’ve given less money for research into it and, as a result, know relatively little about it.
Claire Hopkins, the president of the British Rhinological Society, told me that the science of olfaction, compared to that of vision or hearing, is still in the Stone Age.
But that could change, in part thanks to Hopkins herself. Last March she coauthored an unassuming news alert titled “Loss of smell as marker of Covid-19 infection.”
She was promptly inundated with responses from all over the world reporting the same phenomenon. Less than a year on, and olfaction is one of the hottest scenes in medicine. There’s now even a Global
Consortium for Chemosensory Research, where boffins from more than 60 countries collaborate to get to the bottom of Covid and smell.
Neurologically, it’s our most primal sense: The perception of an odor shoots directly from our nasal receptors into our brains, bypassing the thalamus and immediately triggering a memory or emotion. By contrast, vision, hearing and touch must take several additional synaptic hops. So does taste — but most
of our perception of that sense is actually a by-product of smell in the first place.
The very richness of our smell universe, however, means that we have no vocabulary to describe it adequately. Being at a loss for words — just think back to your most recent wine tasting — we tend to make the mistake of thinking our olfaction is less important than, say, our vision.
And yet, the merest whiff can dredge up long-buried memories of joy or pain. It can tell us if somebody else’s immune system is similar to our own or very different.
It picks up pheromones that trigger fear, aggression, love or intimacy long before the rest of our brain has even formulated a single thought. It’s only when smell is gone that people wake up to its commanding role in our biological, psychological and emotional existence.
And that absence leaves a debilitating void. Many sufferers lose their appetite, confidence, libido and human connections. Some fall into depression. Parosmia can be even worse than anosmia, Hopkins told me, leaving people destabilised, unmoored and estranged.
The opposite condition, called hyperosmia, also exists. Sometimes it just means you’re pregnant, other times that you may have epilepsy, often that you’ve been genetically lucky. That’s the case with Joy Milne, a retired nurse in Scotland.

—Bloomberg