Sequels of COVID-19: An integrative literature review

The strong affinity between the Spike protein of the SARS-CoV-2 virus and the angiotensin-converting enzyme 2 receptor is postulated as one of the main reasons for the high viral transmission rate, leading the WHO to declare COVID-19 as a Public Health Emergency of International Concern and to adopt measures to contain viral spread. Moreover, due to the virus’s pathophysiological mechanism, non-specific symptoms, atypical progression, especially in the elderly and immunocompromised, and a faster and more lethal progression are observed. Additionally, as knowledge about the natural history of the virus infection has advanced, persistent symptoms and/or sequelae causing organic dysfunctions and negatively impacting patients’ quality of life have been noted. In light of this, the objective of this article was to present an integrative review of the main sequels of COVID-19 in the years 2021 and 2022. To achieve this, full articles were searched in the Scientific Electronic Library Online, Biblioteca Virtual em Saúde, and PubMed research databases, in both Portuguese and English languages, using the PRISMA methodology (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), resulting in the selection of 14 articles. Among the results, the following stand out: the pathogenesis of persistent COVID-19 is based on the theory of immune phenomena secondary to infection, abnormal immune response, and the presence of the virus in immunologically privileged sites; prevalent complications include fatigue, dyspnea, subjective cognitive impairment, neurological sequelae, central nervous system inflammatory diseases, and post-viral olfactory dysfunction; evidence of a causal relationship between COVID-19 and subacute thyroiditis was presented; a higher number of complications and hospitalizations were demonstrated in vitamin D-deficient patients; as well as the presence of neuropsychiatric symptoms in the healthcare professional population. In conclusion, a scarcity of