Relevant mechanisms and pathways in the transmission of SARS-CoV-2 infection

Introduction: The type of betacoronavirus that causes the disease COVID-19 is called SARS-CoV-2, it has presented a rapid expansion worldwide, currently generating a public health emergency. Different causes can explain this behavior, such as the type of transmission, which has been debated, with different positions regarding the involvement of aerosol and extrapulmonary pathways. Objective: Consolidate information of the different mechanisms and transmission routes of SARS-CoV-2. Methodology: A narrative review of the literature was carried out with a systematic search in databases such as Pubmed, Embase, ScienceDirect, MEDLINE, CENTRAL and Literatura Latinoamericana y del Caribe en Ciencias de la Salud (LILACS). With MeSH terms "Transmission", "Aerosol", "Betacoronavirus" applying inclusion and exclusion criteria, as well as critical reading with the CASPe tool, 31 articles were selected. Results: The transmission of the virus occurs by contact with drops, fomites and aerosolization, favoring air infection and its permanence even up to 8 hours, being a propagator of the disease. The transmission by blood and fecal contact, is not frequent, but in cases such as performing procedures or requiring a transfusion, are relevant and measures must be taken. Conclusions: All patients should be considered potential transmitting and both mechanical and self-induced aerosol induction should be considered, without requiring an important manipulation of the airway for virus aerosolization and transmission. The measures for the management of the environment must be considered, as well as the possibility of transmission by extrapulmonary route, such as blood and orofecal route.