What is prolonged covid-19 syndrome?
Prolonged covid-19 syndrome
Around 5% of patients suffering from Covid-19 report persistence of symptoms months after the cure. The most frequent clinical manifestations in these patients are: fatigue, dyspnea, cough, changes in smell and taste, joint and muscle pain (arthralgia). It is the prolonged covid-19 syndrome (long covid in Anglo-Saxon medical literature).
They are patients with acute coronavirus infection in the previous months, who report not having recovered normality. They manifest sleep disorders, memory loss, disorientation, difficulty concentrating, fatigue, depression, muscle and joint pain, headache, palpitations, alopecia, and intermittent low-grade fever or fever. Many say they have experienced accelerated aging.
A recent pre-publication from King’s College London, pending peer review, examined 4,182 patients who had had a positive PCR for SARS-CoV-2. The results showed that 13.3% said they had not recovered after four weeks, 4.5% after eight weeks and 2.3% even after 12 weeks.
Chronic Fatigue Syndrome
The post-viral fatigue pattern of these patients with residual COVID-19 is reminiscent of chronic fatigue syndrome, also known as myalgic encephalomyelitis.
Myalgic encephalomyelitis is a poorly defined entity, like a mixed bag for a heterogeneous group of patients who report intense or strenuous fatigue, often after having suffered a viral infection.
It has occasionally been associated with infections by viruses of the herpes family, such as the Epstein-Barr virus, which can cause chronic infections and episodes of reactivation after being latent. It is more frequent in women in the middle age of life.
Of other viruses that cause chronic infections in humans, such as HIV, hepatitis B virus and hepatitis C virus, we know that processes of chronic inflammation and persistent immune activation have been associated with an increase in cellular metabolism and phenomena of early aging, both in certain organs and systemically. It is difficult to accept this hypothesis for a coronavirus, which only produces self-limited infections that remit naturally, unlike HIV or hepatitis B or C viruses.
However, the cytokine storm that can be unleashed after several days of SARS-CoV-2 infection could lead to immune dysregulation and lead to clinical worsening and complications throughout the body. This could lead to an activation of endogenous virus expression and epigenetic changes that would increase cellular metabolism. This appears to be the pathogenesis of postcoronaviral syndrome.
Outpatient follow-up of patients who have had a confirmed SARS-CoV-2 infection will help to better understand the frequency and characteristics of prolonged COVID-19 syndrome. Identifying its causes will provide guidance on possible treatment strategies.