Epidemiology and Etiopathogeny of COVID-19.

Despite the recent announcement of the new pathogenic coronavirus to man, SARS-CoV2, a large number of publications are presented to the scientific community. An organized and systematic review of the epidemiological, etiological, and pathogenic factors of COVID-19 is presented. This is a systematic review using the databases MEDLINE, EMBASE, Web of Science, SCIELO; the descriptors coronavirus, SARS-CoV-2, etiology, epidemiology, pathophysiology, pathogenesis, COVID-19, with publications from December 2019 to January 2021, resulting in more than 800 publications and 210 selected. The data suggest that COVID-19 is associated with SAR-CoV-2 infection, with the transmission of contagion by fomites, salivary droplets, and other forms, such as vertical and fecal-oral. The bat and other vertebrates appear to be reservoirs and part of the transmission chain. The virus uses cell receptors to infect human cells, especially ACE2, like other coronaviruses. Heat shock proteins have different roles in the infection, sometimes facilitating it, sometimes participating in more severe conditions, when not serving as a therapeutic target. The available data allow us to conclude that COVID-19 is a pandemic viral disease, behaving as a challenge for public health worldwide, determining aggressive conditions with a high mortality rate in patients with risk factors, without treatment, but with the recent availability of the first vaccines.

Anatomopathological Aspects and Clinical Correlation of COVID-19: A Systematic Review.

OBJECTIVE: The objective of this systematic review was to analyze the main morphofunctional changes in the involvement of multiple organs in patients infected with SARS-CoV-2, correlating anatomopathological findings with the clinical picture. METHODS: The present study selected articles through electronic search of indexed journals in the PubMed and SciVerse Scopus databases, from December 2019 to May 2020, using the keywords "autopsy," "pathogenicity," and "COVID-19." Two hundred nine articles were identified, and the full texts of 18 articles were reviewed, 5 of them being selected for this review. RESULTS: The ACE2 receptor plays a role in introducing viral material into the cell, having high expression in type II alveoli. Histopathological analyzes of the lungs of patients with COVID-19 show that SARS-CoV-2 produces, in this organ, in addition to an inflammatory process, a diffuse alveolar damage (DAD), which can cause acute respiratory distress syndrome (ARDS). Macroscopically, the lungs become heavier, firmer, and redder. The clinical features of these patients are variable; the most common are respiratory symptoms associated with fever, myalgia, or fatigue. CONCLUSION: The observations points to the consensus that the lungs are the main targets of COVID-19, with morphological and functional changes of interest, including important sequels, and presenting diffuse alveolar damage as a substrate for an unfavorable outcome with ARDS. Changes in micro and macroscopic levels corroborate to the clinical progression of the disease and that these alterations are not specific, which ratify, in addition to the anatomopathological examination, a need to use the association of clinical and epidemiological data for diagnostic confirmation.