For most people, infection with SARS-CoV-2 – the virus that causes COVID-19 – leads to mild, short-lived symptoms, severe respiratory illness, or perhaps symptoms at all. However, some people have permanent symptoms after their infection – this has been termed “prolonged COVID”.
Scientists are still studying COVID for a long time. It is not well understood, although our knowledge about it is growing. Here I take a look at what we have learned about it so far – who is at risk, how common it is and what impact it has.
In explaining who is at risk from prolonged COVID and the mechanisms involved, we may identify appropriate remedies to try – or whether steps taken early in the course of the course may be necessary. reduce illness.
Widespread vulnerability
COVID has long been characterized by a constellation of symptoms, including – variable – shortness of breath, marked weakness, headache, and loss of ability to taste and smell as usual.
A relatively large study of 384 people ill enough to be admitted to hospital with COVID-19 showed that 53 percent remained breathless at follow-up assessment a month or two later, with 34 percent having cough and 69 percent reported being obese.
In fact, early analysis of self-report data submitted through the COVID Symptom Study app suggests that 13 percent of people who experience COVID-19 symptoms have it for more than 28 days , and 4 percent have symptoms after more than 56 days.
Perhaps unsurprisingly, people with a more serious initial onset – characterized by more than five symptoms – appear to be at greater risk for prolonged COVID. Older age and being female also appear to be risk factors for prolonged symptoms, as is a higher body index.
Those who use the app tend to be at the more appropriate end of the population, with an interest in health issues. It is therefore surprising that symptoms are at such a high level one or two months after the first infection. In general, these are not people at high risk from COVID-19.
Another early piece of research (pending peer review) suggests that SARS-CoV-2 may have long-term effects on human organs. But the profile of those affected in this study is different from those who report symptoms through the app.
This study, which looked at a sample of 200 patients who had undergone COVID-19, found soft tissue weakening in 32 percent of human hearts, 33 percent of human lungs and 12 percent of human kidneys. Multiple organ damage was detected in 25 percent of patients.
Patients in this study had an average age of 44 years, and were therefore significantly part of the young, working-age population. Only 18 percent were hospitalized with COVID-19, meaning organ damage could occur even after non-serious infection. It was not necessary to do organ damage either with a disease that causes more severe COVID-19, such as type 2 diabetes and ischemic heart disease.
Find out what’s going on
There are many reasons why people may have symptoms months after a viral illness during a pandemic. But it will be easier to get to the bottom of what is going on inside people for some parts of the body than others.
Where symptoms indicate a specific organ, examination is relatively straightforward. Clinicians can examine the flow of electricity around the heart if someone is suffering from palpitations. Or they can study lung activity – tissue elasticity and gas exchange – where shortness of breath is the main symptom.
To determine whether renal activity has decreased, components in a patient’s blood plasma are compared with those in their urine to measure how well the kidneys filter waste products.
It is more difficult to check for a fat sign. Another recent large study has shown that this symptom is common after COVID-19 – occurring in more than half of cases – and shows that it has nothing to do with the severity of the disease early on.
In addition, trials showed that the people studied did not have higher levels of inflammation, suggesting that it was not a chronic infection or their immune system that worked overtime.
Risk factors for chronic symptoms in this study included being female – according to the COVID Symptom App study – and, interestingly, having a previous diagnosis of anxiety and depression.
While men are at greater risk of serious disease, women may experience more exposure to COVID as long as their different or variable hormone status is manifested. The ACE2 receptor used by SARS-CoV-2 to infect the body is present not only on the surface of respiratory cells, but also on the cells of many hormone-producing organs, including the thyroid, adrenal gland and ovaries.
Some COVID symptoms may long outweigh menopausal symptoms, and hormone replacement by the use of medication as one route to reducing the effects of symptoms. However, clinical trials will be essential to properly determine whether this approach is safe and effective. Applications for such research have been launched.
With so much happening over the past year, we need to separate ourselves from the effects that the virus itself can have on the face of the potential social unrest that this pandemic is causing.
What is clear, however, is that long-term symptoms after COVID-19 are common, and research into the causes and treatments of COVID will be needed long after the onset of COVID-19. out yourself to go down.
Frances Williams, Professor of Genetic Epidemiology and Consultant Rheumatologist Honorary Consultant, King’s College London.
This article is republished from The Conversation under a Creative Commons license. Read the original article.