Copyright@ Gustavo Acosta Altamirano | Biomed J Sci & Tech Res | BJSTR. MS.ID.006075. 29899 Opinion ISSN: 2574 -1241 SARS-CoV-2 and its Transmission Ability Through the Nasal and Oral Cavities Carlos Uriel Torres Estrella 1,2 , Eduardo García Salazar 1,4 , María Guadalupe Frías De León 1 , María del Rocio Acosta Reyes 3 and Gustavo Acosta Altamirano 1,4 * 1 Hospital Regional de Alta Especialidad de Ixtapaluca, Estado de México, México 2 Unidad Profesional Interdisciplinaria de Biotecnología, Instituto Politécnico Nacional (IPN), Ciudad de México, México 3 Centro Geriatrico “Cieneguitas”, San Miguel de Allende, Guanajuato, México 4 Escuela Superior de Medicina, Instituto Politécnico Nacional (IPN), Ciudad de México, México *Corresponding author: Gustavo Acosta Altamirano, Hospital Regional de Alta Especialidad de Ixtapaluca, Estado de México, México DOI: 10.26717/BJSTR.2021.37.006075 Opinion Since the beginning of the pandemic caused by the SARS-CoV-2 virus, it was identified that its ligand Spike Protein (S protein) is the receptor of the Angiotensin-Converting Enzyme 2 (ACE2), which is present in epithelial cells of the nasal mucosa, the surface of the tongue in the oral cavity, the pharynx, and the salivary glands [1]. These last have a higher ACE2 expression, which facilitates the virus to infect a person. Because saliva is a secretion from the oral cavity produced by the parotid, sublingual, and submandibular glands, it is in constant contact with perioral tissue, such as the tongue, which due to its mobility, facilitates saliva to be in contact with the entire oral cavity [2]. The presence of viral RNA in saliva has allowed the detection of the SARS-CoV-2 virus in the early stages of infection and promptly identify asymptomatic individuals [2,3]. Saliva also contains IgA and IgG isotype antibodies which could be relevant in immunized people against SARS-CoV-2 [2]. In general, if a healthy person comes into contact with aerosols contaminated with the virus, the following alternatives can occur: a) If the virus enters through the open oral cavity, it will come into contact with saliva. The viral particles could go into the digestive tract because the epiglottis blocks saliva access to the lungs [4], thus reinforcing findings of the virus in feces [5] and gastrointestinal symptoms. b) The virus may be introduced through the nostrils. Since it is the first route of contact with the respiratory system, it can replicate in nasal cells expressing ACE2 receptors and migrate to the lower respiratory tract during inhalation. Even ARTICLE INFO ABSTRACT Abbreviations: ACE2: Angiotensin-Converting Enzyme 2; S Protein: Spike Protein; TMPRSS2: Transmembrane Serine Protease 2 Received: July 31, 2021 Published: August 06, 2021 Citation: Carlos Uriel Torres Estrella, Eduardo García Salazar, María Guadalupe Frías De León, María del Rocio Acosta Reyes, Gustavo Acosta Altamirano. SARS-CoV-2 and its Transmission Ability Through the Nasal and Oral Cavities. Biomed J Sci & Tech Res 37(5)-2021. BJSTR. MS.ID.006075.