In 2020, the world was battling COVID-19 and many countries introduced lockdowns or restrictive measures. Three years later, such lockdowns and restrictive measures are luckily not required anymore to protect us from COVID-19, but did you know that millions of people (65 – 144 million) are still living in lockdown or under restrictive measures as a result of their COVID-19 infection? These people suffer from long COVID.
What is long COVID?
According to the World Health Organization, long COVID is defined as the continuation or development of new symptoms 3 months after the initial COVID-19 infection, with these symptoms lasting for at least 2 months with no other explanation. More than 200 symptoms have been reported, but common symptoms include fatigue, headache, cognitive symptoms, chronic joint and muscle pain, and loss of smell. All these symptoms have a major impact on quality of life. Long COVID is a disabling disease and leaves some patients home- or even bed-bound. Long COVID patients are thus still living in lockdown or under restrictive measures as they are often too ill to leave the house or live their life the same as before their COVID-19 infection.
Similarities to ME/CFS
A subset of patients with long COVID share the same clinical presentation as patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). According to recent studies, approximately half of long COVID patients meet the criteria for ME/CFS. Overlapping symptoms include fatigue, cognitive symptoms, post-exertional malaise, and chronic joint and muscle pain. Next to similarities in clinical presentation between these patient populations, biological similarities have also been described. For instance, both long COVID and ME/CFS are characterised by abnormalities in the central and autonomic nervous system, immune system, and energy metabolism. Like ME/CFS, long COVID predominantly affects women. Moreover, in a subset of patients with ME/CFS, disease onset occurred after a viral infection as is the case for long COVID.
Is there indeed a new pandemic on the horizon?
The truth is: we don’t know yet. As long COVID is a rather new disease, we cannot say anything about recovery rates on the long term. One study reported that 85% of patients with long COVID 2 months after acute infection still presented with symptoms at 1-year follow-up. This is consistent with our knowledge about ME/CFS from which many patients never fully recover. It is thus expected that long COVID will drastically increase the number of people suffering from chronic pain and ME/CFS compared to pre-COVID-19 times. Thereby, long COVID will probably have a long lasting effect on global society and economy by the direct and indirect costs related to these conditions. Research is thus needed to better understand the pathophysiological mechanisms underlying long COVID and eventually develop effective treatments so that quality of life improves and thereby societal and economic burden decreases.
Jolien Hendrix
PhD student at Vrije Universiteit Brussel and KU Leuven
2023Pain in Motion
References and further reading: http://www.sciencedirect.com/science/article/pii/S...
Komaroff AL and Lipkin WI (2023) ME/CFS and Long COVID share similar symptoms and biological abnormalities: road map to the literature. Front. Med. 10:1187163. doi: 10.3389/fmed.2023.1187163
https://www.frontiersin.org/articles/10.3389/fmed....
Jason LA, Dorri JA. ME/CFS and Post-Exertional Malaise among Patients with Long COVID. Neurol Int. 2022 Dec 20;15(1):1-11. doi: 10.3390/neurolint15010001. PMID: 36648965; PMCID: PMC9844405.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9844405/
Astin, R., Banerjee, A., Baker, M. R., Dani, M., Ford, E., Hull, J. H., Lim, P. B., McNarry, M., Morten, K., O'Sullivan, O., Pretorius, E., Raman, B., Soteropoulos, D. S., Taquet, M., & Hall, C. N. (2023). Long COVID: mechanisms, risk factors and recovery. Experimental Physiology, 108, 12– 27.
