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Long covid—mechanisms, risk factors, and management

BMJ 2021; 374 doi: https://doi.org/10.1136/bmj.n1648 (Published 26 July 2021) Cite this as: BMJ 2021;374:n1648

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Covid-19 can be a prolonged illness

Dear Editor

Motivated by the interesting article published by Harry Crook, Sanara Raza, Joseph Nowell, Megan Young and Paul Edison in BMJ: Long covid — mechanisms, risk factors, and management, we wish to express our considerations in this regard.

There are studies that have characterized the prolonged presence of genetic material or persistent viral shedding which does not necessarily imply that there is an active infection. As a mechanism for such viral persistence, a cellular transport pathway is proposed related to the formation and release of extracellular vesicles that remain loaded with viral particles, which cause this genetic material to remain hidden for a certain period of time and later begin to spread again. The immune response triggered by the first contact with the coronavirus triggers an immune response that confers a certain degree of protection in future contacts, with this virus depending on the immunocompetence of the infected patient, which in many cases translates into reinfection asymptomatic or with less severe symptoms.

This article published by BMJ compiles what the global scientific community has fund in relation to reinfection in those patients recovered from COVID-19, as well as the entire immune mechanism related to this process and the possible causes of a prolonged COVID infection.

References
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Competing interests: No competing interests

30 July 2021
Yeneys Pujol-Ensenat
Head of the Intensive Care Unit. Assistant Professor
Santos-Pena Moisés A.
Dr. Gustavo Aldereguia University General Hospital. WHO Collaborating Center
Ave 5 of September and 51-A Street. Cienfuegos. Cuba 55100