It’s a mystery. Science advances in its understanding, but persistent COVID remains unknown in many respects. It is not known why it involves sequelae and other medical complications that last weeks or months after initial recovery from infection. And it is not very clear why it affects some patients and not others.
It is precisely to this question that it seeks to answer, as far as possible, Frances Williams, Professor of Genomic Epidemiology (King’s College London, UK), through an article originally published in ‘The Coversation’ earlier this year.
Persistent COVID is characterized by an accumulation of symptoms, including, variably, shortness of breath, marked fatigue, headache, and loss of the ability to taste and smell normally, and can last for weeks.
“Scientists have been researching this variant of the disease for a long time. Although there are still dark spots, our knowledge about it is increasing“Explains Williams, for whom, predictably,”people with a more severe illness initially, characterized by more than five symptoms, seem more exposeds. The old age and female sex They also appear to be risk factors for prolonged symptoms, as do have a higher body mass index”.
At least that is what emerges from the initial analysis of data sent through the application ‘COVID Symptom Study’, managed by both researchers from King’s College London and the British National Health System
The organ study approach
However, as Williams shares, other preliminary research work (pending peer review) suggests that SARS-CoV-2 could also have a long-term impact on organs such as the heart, lungs or kidneys . “But the profile of those affected in this study is different to those who reported symptoms through the application, “says the expert.
And, in this case, the study patients “had an average age of 44 years, so they represented a significant part of the young population of working age. Only 18% had been hospitalized with covid-19 ”. “Meaning that organ damage can occur even after a non-serious infection“, Add.
The symptom of fatigue
As if that were not enough, Frances Williams, also includes in her dissertation the results of another recent large-scale study focused on fatigue. “This symptom is common after COVID-19, which occurs in more than half of the cases, and appears to be unrelated to the severity of the early illness. The risk factors for long-lasting symptoms in this study included being female and, interestingly, having a previous diagnosis of anxiety and depression”, Explains the researcher.
While men are at higher risk of serious infection, women are more affected by persistent COVID may reflect a different or changing hormonal status. “The ACE2 receptor that SARS-CoV-2 uses to infect the body is present not only on the surface of respiratory cells, but also on cells of many hormone-producing organs, such as the thyroid, adrenal gland, and ovaries. Williams says.
“With everything that has happened in the last year, we will have to separate which impacts come from the virus itself and which could be the consequence of the massive social disruption caused by this pandemic. However, what is clear is that long-term symptoms after COVID-19 are common, and that persistent COVID causes and treatments will likely need to be investigated long after the outbreak has subsided, “he concludes. .