Airborne Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 and Protection of Health Care Professionals

Abstract

To the Editor: Coronavirus disease 2019 (COVID-19), a disease caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus, has raised questions concerning biosafety, especially relating to the use of personal protective equipment (PPE), in the context of PPE shortage in the world.1 This text draws attention to the risk of airborne transmission (by aerosols) of the pathogen, which implies expanding protection measures for health care professionals (HCPs), the “most valuable resource”2 in coping with the disease. So far, it is understood that the spread of SARS-CoV-2 occurs primarily by droplets (5–10 μm in diameter) and by contact,1 which require the adoption of relevant precautionary measures to prevent virus transmission. Additional concern, in relation to the dissemination of COVID-19, exists regarding inhalation of aerosols, particles with a diameter less than 5 μm, which remain airborne for a long time and may move distances greater than 1 m.1 It has been postulated that air transmission of SARS-CoV-2 occurs in special situations, such as endotracheal intubation, noninvasive ventilation, airway aspiration, swab collection (oral or nasopharynx), and bronchoscopy.1 In these contexts, the use of an N95 respirator, as a replacement for the surgical mask, is indicated for the protection of HCPs. Despite recommendations of the World Health Organization,1 prioritizing the precautionary principle by contact and by droplets, there are gaps regarding the possibility of airborne transmission of COVID-19. In fact, other situations with the potential to spread the disease by aerosols have been proposed, related to sneezing, coughing, and wheezing (dyspnea).3 In addition, the study of aerodynamics of infective particles containing SARS-CoV-2, in a Chinese hospital, identified the virus more than 3 m from the bedside of patients with COVID-19, and even in external areas of the hospital.4 Another study demonstrated dispersion, of up to 4 m, of SARS-CoV-2 aerosols in a COVID-19 patient hospitalization unit.5 These results supported the adoption of measures for aerosol contagion prevention, which result in less HCPs if they get infected by the pathogen.5 Furthermore, the high viral loads in the airways of patients with COVID-19 and the disease cases exponential rate of growth indicate that airborne transmission of COVID-19 is much more important, epidemiologically, from what has been reported. Recognizing the likely underestimation of airborne transmission of SARS-CoV-2 and the major risk of illness of people exposed to the pathogen, it is recommended that all HCPs caring for confirmed or suspected COVID-19 patients at different levels in health care be offered appropriate PPE to prevent aerosols, with emphasis on N95 respirators. Rodrigo Siqueira-Batista, PhD Department of Medicine and Nursing Universidade Federal de Viçosa Viçosa, Minas Gerais, Brazil School of Medicine Faculdade Dinâmica do Vale do Piranga Ponte Nova, Minas Gerais, Brazil [email protected]Oswaldo Jesus Rodrigues da Motta, MA Nucleus of Bioethics and Applied Ethics Universidade Federal do Rio de Janeiro Rio de Janeiro, BrazilLuciene Muniz Braga, PhDAndréia Patrícia Gomes, PhD Department of Medicine and Nursing Universidade Federal de Viçosa Viçosa, Minas Gerais, Brazil