Some people who have been infected with SARS-CoV-2 show persistent symptoms that continue to manifest several months later.
The emergence of the current crisis caused by the coronavirus (SARS-CoV-2) has meant an extraordinary change in our way of life.
From the moment the World Health Organization declared the situation as a pandemic, information about the disease associated with this pathogen (covid-19) began to spread like wildfire and become an inherent part of our daily lives. In such a short notice, a large part of the population had to learn about the hygiene measures that would allow to contain its very rapid progression.
Certainties And Uncertainties About Covid-19
Currently the volume of scientific researches on coronavirus is too many, as thousands of specialists have devoted themselves to unraveling its mysteries. The initial uncertainty begins to give way, at least, to a few certainties.
Among them, the most common symptoms of covid-19 are muscle pain, fatigue, fever, respiratory problems, headache, and loss of taste or smell; as well as that its mortality rate varies according to sociodemographic variables.
The times in which the infection develops are also known: its incubation tends to last between four and seven days after the virus enters the body (with a maximum time window of two weeks). At this time, the first changes in health status are usually identified.
As days go by, the pathogen disappears from the body and the person progressively recovers their previous physical conditions. This is the most frequent form of evolution. On the other hand, approximately 30% of the cases would involve asymptomatic patients. These often do not even receive a diagnosis (although they could transmit the disease to others).
However, with the unfortunate accumulation of cases that we are experiencing, a worrying phenomenon is beginning to emerge: some people show persistent symptoms, especially related to intense fatigue. This symptom of the disease continues to be unknown in terms of its evolution and causes, but its prevalence increases as the virus spreads across the planet.
When Do We Consider That A Symptom Persists?
Persistent symptoms of covid-19 are understood to be those that last for several months after the recovery of the acute infection process, maintaining an intensity that determines the day-to-day life of patients. It is not a unique phenomenon though, as there was already evidence that certain viruses and bacteria could affect humans in long term.
Some examples would be the SARS-CoV detected in Asia during 2003 (which eventually spread to other countries) or the MERS-CoV (Saudi Arabia, 2012). Other infections, such as the Epstein-Barr virus or the H1N1 influenza virus (to name a few), have also demonstrated their ability to generate persistent symptoms. In all these cases, fatigue is usually the most resistant symptom to remission, which has motivated the generic diagnostic label of post viral fatigue.
People who suffer from it report a generalized fatigue, need to rest and have difficulties in standing for long periods. In some cases, the intensity of the symptom reaches such a magnitude that it makes it impossible to carry out daily activities.
In addition to all these, difficulties of diagnosis and evaluation implicit in fatigue due to its deep subjective component. This can contribute to the frequent feeling of helplessness and despair in the person suffering from them.
What We Know About Persistent Symptoms Of Covid-19
In the case of SARS-CoV-2, some studies indicate that 87% of patients maintain at least one symptom two months after the first diagnosis. Studies are even beginning to be published comparing this form of presentation with myalgic encephalomyelitis (chronic fatigue syndrome), a very disabling and poorly understood disease.
This persistence has been observed both among those who showed a mild condition and among those who had greater difficulties during the acute process. However, it has been more frequently documented among women and among those admitted to intensive care units. These latter patients often require a longer recovery time. The severity of the disease and the sex, therefore, could be important to understand this intense fatigue.
What’s Behind Post Viral Fatigue?
The first explanatory hypotheses investigate the inflammatory and immunological responses that arise naturally during infectious processes. These can occasionally get out of control and lead to a dangerous cytokine storm.
This mechanism in SARS-CoV-2 is attracting the attention of specialists who seek to solve the unknown. The ability of the virus to cross the blood-brain barrier, and certain mediating genetic factors, could also explain the appearance of long-lasting neurological symptoms (such as fatigue).
Lastly, there is research in which the role of secondary psychological problems (anxiety, depression, etc.) is highlighted as factors that contribute to intensification the subjective experience of fatigue and that tend to accompany it while it persists.
Likewise, many of those who suffered from the disease and suffer residual symptoms report suffering social stigma, the product of fear and ignorance. As science prepares to empower people with persistent difficulties, educating the public about the infection and its consequences remains essential.