Long-lasting symptoms are not unique to the SARS-Cov-2 virus infection causing COVID-19. In fact, Melissa Heightman, who set up the first post-Covid-19 clinic at University College London Hospitals, says it’s common among most infectious outbreaks. Writing in BBC Future she suggests a clue to long term COVID may lie in the brain.
The Long Tail of Epidemics is a Common Event
Melissa Heightman believes almost all infectious outbreaks leave behind a proportion of patients who remain chronically unwell. And, quite amazingly, their symptom patterns are similar to long COVID and scientists believe they know why.
The tale begins in 2004, when the SARS outbreak briefly spread to Toronto, Canada. It affected 251 people, mainly healthcare workers. But more than a year later 50 of them were still unwell. A consultant there asked Harvey Moldofsky, a neuroscientist at the University of Toronto for advice.
‘It was a mystery,’ Harvey Moldofsky recalls. ‘Even though there was no lingering lung inflammation, they felt weak, extremely fatigued. They had aches and pains all over their bodies, and they were completely unable to work.’
Uncovering the Clue to Long Term COVID in the Brain
Then Harvey Moldofsky noticed something telling. All 51 people with the mysterious condition were sleeping very poorly. Now he knew this was a sign of widespread inflammation in the brain, but he did not have resources to continue.
The breakthrough clue to long term COVID lying in the brain came some time later. That was when Chinese scientists discovered fragments of SARS virus genetic material in brain cells of patients with post-SARS syndrome. ‘We know there’s a direct connection from our nose to the brain, called the olfactory nerve,’ Harvey Moldofsky explains.
‘And this is probably how the virus got directly into the circulation of the brain,’ he adds. ‘I believe those viral fragments were interfering with how their brains were functioning, which would explain the poor sleep quality and other issues.
Related
Persistent Symptoms of the COVID Long Tail
Numbing Effect of Enduring COVID Fatigue
Fatigue Trauma of Non-Hospitalized COVID
Preview Image: The Olfactory (Cranial) Nerve
