The influenza virus, SARS-CoV-2, and the airways: Clarification for the otorhinolaryngologist.
Eur Ann Otorhinolaryngol Head Neck Dis
; 137(4): 291-296, 2020 Sep.
Article
in English
| MEDLINE | ID: covidwho-437020
ABSTRACT
The influenza virus and SARS-CoV-2 cause trivial upper and severe lower respiratory infections (Influenza virus 290,000 to 650,000 deaths/year). These viruses come into contact with the airways either by direct projection, by secondary inhalation of airborne droplets, or by handling (fomites). The objective of this article is to clarify the mechanisms of production and penetration of droplets of secretions emitted during all expiratory phenomena likely to transport these viruses and come into contact with the respiratory mucosa. The droplets>5µm follow the laws of ballistics, those<5µm follow Brownian motion and remain suspended in the air. The aerosols of droplets are very heterogeneous whether the subject is healthy or sick. During an infectious period, not all droplets contain viral RNA. If these RNAs are detectable around patients, on surfaces, and in the ambient air at variable distances according to the studies (from 0.5m to beyond the patient's room), this is without prejudice to the infectious nature (viability) of the virus and the minimum infectious dose. There is a time lag between the patient's infectious period and that of RNA detection for both viruses. Subsequently, the inhaled particles must meet the laws of fluid dynamics (filtration) to settle in the respiratory tree. All of this partly explains the contagiousness and the clinical expression of these two viruses from the olfactory cleft to the alveoli.
Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Orthomyxoviridae
/
Otolaryngology
/
Pneumonia, Viral
/
Coronavirus Infections
/
Bodily Secretions
/
Respiratory Mucosa
/
Influenza, Human
/
Betacoronavirus
Type of study:
Prognostic study
Limits:
Humans
Language:
English
Journal:
Eur Ann Otorhinolaryngol Head Neck Dis
Year:
2020
Document Type:
Article
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