Posted on 05/06/2021 10:06:10 AM PDT by RC one
Loss of smell or taste, or both, is common in COVID-19 infected patients, particularly in patients with mild symptoms. Although research has focused on the causes underlying lung infections in COVID-19 patients, the causes of neurological symptoms have remained a mystery.
Researchers have now explained the mechanisms involved in the loss of smell (anosmia) in patients infected with SARS-CoV-2 at different stages of the disease, in an article published in Science Translational Medicine, “COVID-19-related anosmia is associated with viral persistence and inflammation in human olfactory epithelium and brain infection in hamsters.”
Using noninvasive nasal brush sampling, scientists at the Institut Pasteur, CNRS, Inserm, University of Paris, and Assistance Publique – Hôpitaux de Paris, examined the nasal linings in 11 patients with COVID-19 reporting loss of smell and detected SARS-CoV-2 viral particles and inflammation in several cell types in the lining of the nasal cavity (olfactory neuroepithelium) including sensory neurons. The researchers showed SARS-CoV-2 infects and multiplies in the olfactory epithelium of hamsters and in individuals with COVID-19 for several months after infection.
In four patients that developed persistent loss of smell, the authors detected lasting SARS-CoV-2 presence in the nasal mucosa, even when the virus RNA could not be detected in nasopharyngeal swabs through routine diagnostic RT-qPCR. This unexpected finding prompted the authors to suggest that diagnosis of SARS-CoV-2 by nasal brushing can complement nasopharyngeal swabbing for PCR testing in patients with loss of smell.
The study revealed the step-by-step mechanism of COVID-19-related loss of smell in chronological order. Upon viral infection, the cilia on the surface of sensory neurons disappear. These cilia are slender projections of the cell’s bounding membrane that latch onto odorant molecules and constitute the first step in the perception of smell. The authors showed that SARS-CoV-2 can persist in the nasal sensory neurons in humans for several months after the symptoms of the disease have resolved.
The nasal epithelium is a highly organized bed of flattened cells that makes smelling possible. The authors showed SARS-CoV-2 infection disrupts the organization of the nasal epithelium by inducing programmed cell death (apoptosis).
“We also found that this inflammatory process that takes place in the nasal cavity spreads to the olfactory bulb,” the authors noted. The olfactory bulb constitutes the first cerebral relay station of the olfactory system. These findings are consistent with other studies on deceased patients with COVID-19, where the olfactory bulb shows inflammatory signatures such as microgliosis.
The authors showed SARs-CoV-2 infection of nasal sensory neurons and subsequent infection of the olfactory bulb act as a portal for its entry into more remote regions of the brain such as the brainstem and the cerebral cortex, through a process called “retrograde invasion.”
“The findings we obtained are clinically relevant in the care to patients with COVID-19, since olfactory function loss could be regarded as a sensitive sign of persistent viral infection, and should be considered in-patient management,” the authors noted.
Does the flu do that too? Does anyone know?
That's the first I've heard that particular detail.
I had mild symptoms. Tested positive, but it didn't really impact me. I had fatigue and lost taste and smell, but that was it.
My wife was hit harder. Knocked flat for two weeks, with fatigue and brain fog persisting for weeks afterward. Her taste and smell were never affected.
Hot showers with water on your face.
Helps so much when you have a cold.
BOOOKbump
Don’t breathe or sneeze on me.
Suuure, it only lingers in the nose. Can’t infect anyone, right? Just like Ebola lingers in the genitals but suddenly pops out months and years later.
It sounds like a nasal irrigation device like Navage could be useful
It’s a bizarre virus but I would expect a biological weapon that originated from a bat to have weird symptoms. I have read that it it coexists with bats somehow too, it doesn’t kill them and they don’t kill it despite the fact that they generate 106 degree temperatures during flight. probably explains why it isn’t stopped in its tracks during summer like the flu tends to be.
or maybe nasal steroids?
“Duck Duck Go” has some answers:
https://pubmed.ncbi.nlm.nih.gov/23948436/
https://www.news-medical.net/health/COVID-19-and-Smell-Loss-(Anosmia).aspx
https://www.bbc.com/news/health-53810610
https://www.healthline.com/health/anosmia#causes
My parents both had it third week January 2020 before people really knew it was here. Dad was 94 then and got extremely ill and was hospitalized with pneumonia. They kept having to put him on oxygen at night which was baffling too back then. He was only there for 3 days however.
Mother insisted on staying with him constantly during his 3 days in hospital. She then became ill at home and some sort of cocktail got her over it. Again we had no idea they could have had Covid, it was too new and they’re in Lincoln, NE. Mom was 92 then.
Both of them lost their sense of taste for months. At least 3-4 and even after that things didn’t taste the same to them.
My father even though he was 94, he’s 95 now, was so stumped he didn’t bounce back as he had done years past. Well now we know why. My parents just don’t get ill. This I believe was brought in by relatives from Chicago visiting that Christmas 2019.
So their experience doesn’t fit the article.
I have a loss of taste and smell every time I’m forced to wear a fricking mask. I’ve been in some SE Asia meat markets where the smell caused you to lose taste for all foods. Are our supermarkets turning into SE Asia? Inquiring noses want to know.
Interesting, reading the second one now. I meet quite a lot of people that have had Covid and loss of smell seems to be pretty common among them though not universal.
My wife’s nurse Monday complain about her smell capabilities not recovering. She was infected 4 months ago by her son.
I’m just hypothesizing here but a person in their 90s will require more time to mount an effective antibody response to the invading pathogen than a person in their 30s-40s due to thymic involution. Since it takes more time to respond to the invading pathogen, the invading pathogen has more time to do damage to the host. I wonder if they just had more of these olfactory cells killed and will, consequently, need more time to recover.
My own research has led me to the conclusion that the Chinese knew the covid had escaped the Wuhan lab somewhere around October 4th. It was probably circulating around China as early as September 2019, perhaps earlier. It was early enough to infect people in the United States at Thanksgiving 2019.
My nephew was hospitalized around that time with a persistent pneumonia. He was 12 years old at the time and fit as a fiddle. He’s bounced back well but it just came out of the blue as he has no other health problems whatsoever.
The one thing I have noticed that seems to be universal about covid is that it isn’t really universal. It seems like the stories are somewhat similar but some people definitely had milder cases than others. I have read that it is dose dependent-people that suck in a larger viral load/infectious dose tend to have worse symptoms and elderly folks of course seem to be much more susceptible. and then there’s the comorbidity factor.
I have heard personally from 2 people that said there smell and taste was enhanced and they could not stand to eat most things because they were tasting the chemical in the food. One person still cannot drink sodapop 5 months after CHIVI.
Oops Chivi caused me to spell their incorrectly.
What was so odd to all of us is that my father is a retired dentist, my sister was a dental hygienist and none of us could figure out what could cause such a symptom. It wasn’t until weeks later we found that’s exactly what Covid does.
Still when you consider all we went through in 2020 and the elderly that died you can imagine how fortunate we are to still have my parents here with us.
And how they actually recovered in relatively short time. Then the hospital didn’t even test for Covid they couldn’t. And it wasn’t even on their minds. Or mine then despite I heard of Covid by then from War Room. It didn’t compute.
It was most definitely here by that Fall of 2019. The Chinese knew about it. They didn’t tell the world obviously and how better to infect a planet than by flying planes loaded with disease all over our world.
I remember reading an article where airplane pilots started comparing stories. Many of them had become ill in early Fall and chalked it up to flu or cold but in hindsight it all made sense they’d been exposed to Covid.
I’m so grateful your nephew recovered. Most kids don’t even feel symptoms. Sadly there’s still so much we can’t count on as truth.
What a world we live in.
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