Shortly after the first wave of the Covid-19 pandemic, some patients began to show persistent symptoms after resolution of the acute infection. These clinical manifestations remind us internists of what also occurs in other infections, such as those produced by Epstein-Bar, Coxiella burnetti or Lyme disease, tuberculosis…. In many other infectious diseases the organism undergoes changes produced by the germ responsible and it takes a long time for it to recover and remodel itself back to normal. We are currently studying whether these symptoms we are seeing are related to Covid itself, to indirect effects of the disease on other organs, or to the impact of the pandemic situation. To define this situation, the term #LongCOVID was proposed in May 2020.
What is long Covid or post-Covid syndrome?
It is currently a relevant health problem that requires a response at both scientific and care level, whose alterations produce an impact on the patient’s health, in the medium and long term.
In our country it has been reported that 2-3 months after infection, only 40% of patients have returned to work. Population-based studies in the United States, comparing groups [cohorts] of patients hospitalized for COVID-19 with patients hospitalized for other causes (including cohorts with viral infections), show that greater subsequent medical care is required and also an increase in the frequency of hospital readmissions, in addition to higher mortality.
Importance of Covid-19 vaccination: prevents later persistent symptoms and reduces severity
The best way to prevent post Covid complications is to prevent Covid-19. Vaccination promotion campaigns should indicate that preventing Covid-19 also prevents subsequent persistent symptoms with potential long-term health effects. Most vaccinated patients remain asymptomatic after Covid-19 infection.
Also, unvaccinated patients develop a more severe picture upon infection, and post-Covid syndrome is more frequent and important in patients with severe disease who have required hospitalization (currently unvaccinated inpatients in almost all cases). Therefore, it is of vital importance that the population understands the need to comply with the regulated vaccination.
When is a patient considered to have post-Covid syndrome?
The CDC and WHO propose the generic use of “post-Covid conditions” for health consequences that persist four weeks after acute infection. In contrast, the British National Institute for Health and Care Excellence (NICE) proposes as an operational definition the term “long-COVID”, which encompasses persistent symptoms 4 weeks after acute infection, in the absence of another etiological diagnosis. This term would include “ongoing symptomatic COVID-19” for signs and symptoms between 4 and 12 weeks after acute infection and “post-COVID syndrome” for persistence for more than 12 weeks.
Finally, there seems to be more consensus towards the duration of 12 weeks after infection to establish the diagnosis of post-COVID syndrome.
After Covid-19 the symptoms and signs that patients have may be related to other processes, which may be independent or triggered by the infection. Identifying these other diagnoses is essential to distinguish post-Covid syndrome and to design the best care and therapeutic approach.
The pathophysiology of COVID infection affects several interrelated mechanisms, such as the respiratory system and related disorders such as hypoxia (lack of oxygen). Coagulation alterations, generalized inflammation with immune system response, etc. are simultaneous phenomena that affect both the cardiovascular and neurological systems, mainly. However, the complex part of these consequences on the different organs does not make it strange that later symptoms may arise that will be identified over time, and with the change in the profile of the disease.