Analysis of post COVID-19 condition and its overlap with myalgic encephalomyelitis/chronic fatigue syndrome

Abstract

Background: The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) disease (COVID-19) triggers the development of numerous pathologies and infection-linked complications and exacerbates existing pathologies in nearly all body systems. Aside from the primarily targeted respiratory organs, adverse SARS-CoV-2 effects were observed in nervous, cardiovascular, gastrointestinal/metabolic, immune, and other systems in COVID-19 survivors. Long-term effects of this viral infection have been recently observed and represent distressing sequelae recognised by the World Health Organisation (WHO) as a distinct clinical entity defined as post-COVID-19 condition. Considering the pandemic is still ongoing, more time is required to confirm post COVID-19 condition diagnosis in the COVID-19 infected cohorts, although many reported post COVID-19 symptoms overlap with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Aims of review: In this study, COVID-19 clinical presentation and associated post-infection sequelae (post-COVID-19 condition) were reviewed and compared with ME/CFS symptomatology.

Key scientific concepts of review: The onset, progression, and symptom profile of post COVID-19 condition patients have considerable overlap with ME/CFS. Considering the large scope and range of pro-inflammatory effects of this virus, it is reasonable to expect development of post COVID-19 clinical complications in a proportion of the affected population. There are reports of a later debilitating syndrome onset three months post COVID-19 infection (often described as long-COVID-19), marked by the presence of fatigue, headache, cognitive dysfunction, post-exertional malaise, orthostatic intolerance, and dyspnoea. Acute inflammation, oxidative stress, and increased levels of interleukin-6 (IL-6) and tumor necrosis factor α (TNFα), have been reported in SARS-CoV-2 infected patients. Longitudinal monitoring of post COVID-19 patients is warranted to understand the long-term effects of SARS-CoV-2 infection and the pathomechanism of post COVID-19 condition.

Keywords: Chronic fatigue syndrome; Coronavirus; Fatigue; Myalgic encephalomyelitis; Post COVID-19 condition; Post-infection; SARS-CoV-2; Sequelae.

Graphical abstract

Fig. 1

SARS-CoV-2 induces multiple organ failure. Viral particles and associated cytokines (“cytokine storm”) provoke development of long-lasting complications, including chronic fatigue.

Fig. 2

Immune system responses to SARS-CoV-2 and associated complications. Red arrows indicate abnormal or dysfunctional signalling associated with severity of COVID-19. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)