Corona Luftburet eller inte?
Kan de på Flashback med fil kand/doktorand/kunniga i mikrobiologi sammanställa/ge ett svar på detta med hjälp av dessa medicinska studier/journaler?
En annan sak är Corona extrema smittsamhet. Har WHO´s "forskare" rätt eller "tillrättalägger" de definitionen för att inte skapa panik? Räcker definitionen kontaktsmitta/droppsmitta? Mörkar FHM?
Har Sven Britton på Karolinska institutet helt/delvis fel när han går ut och definierar corona som "luftburet"?
https://norrahalland.se/kand-professor-corona-ar-luftburet/
Infekterade luftvägar, snabb andning, luftfuktighet. Coronas distribution samt halveringstid som aerosol via andning/hosta?
Frågorna (~Är Corona luftburet):
Hur stort är corona viruset?
Vilka storlekar har dropparna vilka viruset färdas på?
Hur beter sig dropparna i luft?
Hur beter sig dessa droppar när de torkar?
Vilka storlekar distribueras/vilka andas inte in/varför?
Hur distribueras dropparna? Vanlig utandning? (Vilket Svenska Agnes Wold, Professor samt doktorand inom mikrobiologi påstår.)
Första frågan kan jag svara på :
Forskare har med hjälp av elektron mikroskop, mätt Coronas sfäriskt formade partiklar - Virionerna [Viruspartikel].
Diameterna på dessa visade sig då variera, de minsta partiklarna mätte 0.06 microner (60 nanometer), de största på 0,14 microner (140 nanometer).
Ett hårstrå mäter ungefär 100 microner i diameter.
Ref.
A Novel Coronavirus from Patients with Pneumonia in China, 2019
https://www.nejm.org/doi/full/10.1056/NEJMoa2001017
Artiklar/Journaler/Studier :
En annan lättläst artikel :
Kan de på Flashback med fil kand/doktorand/kunniga i mikrobiologi sammanställa/ge ett svar på detta med hjälp av dessa medicinska studier/journaler?
En annan sak är Corona extrema smittsamhet. Har WHO´s "forskare" rätt eller "tillrättalägger" de definitionen för att inte skapa panik? Räcker definitionen kontaktsmitta/droppsmitta? Mörkar FHM?
Har Sven Britton på Karolinska institutet helt/delvis fel när han går ut och definierar corona som "luftburet"?
https://norrahalland.se/kand-professor-corona-ar-luftburet/
Infekterade luftvägar, snabb andning, luftfuktighet. Coronas distribution samt halveringstid som aerosol via andning/hosta?
Frågorna (~Är Corona luftburet):
Hur stort är corona viruset?
Vilka storlekar har dropparna vilka viruset färdas på?
Hur beter sig dropparna i luft?
Hur beter sig dessa droppar när de torkar?
Vilka storlekar distribueras/vilka andas inte in/varför?
Hur distribueras dropparna? Vanlig utandning? (Vilket Svenska Agnes Wold, Professor samt doktorand inom mikrobiologi påstår.)
Första frågan kan jag svara på :
Forskare har med hjälp av elektron mikroskop, mätt Coronas sfäriskt formade partiklar - Virionerna [Viruspartikel].
Diameterna på dessa visade sig då variera, de minsta partiklarna mätte 0.06 microner (60 nanometer), de största på 0,14 microner (140 nanometer).
Ett hårstrå mäter ungefär 100 microner i diameter.
Ref.
A Novel Coronavirus from Patients with Pneumonia in China, 2019
https://www.nejm.org/doi/full/10.1056/NEJMoa2001017
Artiklar/Journaler/Studier :
Citat:
Infections by Bio-aerosols
http://ldh.la.gov/assets/oph/Center-PHCH/Center-CH/infectious-epi/HAI/InfectionsbyAerosolsDropletsHandout.pdf
Bio-aerosol Size Bio-aerosols size and reach into the Respiratory Tract:•
>10 μm in aerodynamic diameter blocked by nasal region.
Between 5 and 10 μm deposit in the upper respiratory system.
≤ 5 μm can reach the alveoli and cause lower respiratory tract infectionBased on size and persistence as an aerosol,
the World Health Organization uses a particle diameter of 5 𝜇m to delineate between •Airborne (≤ 5 𝜇m) •Droplet (> 5 𝜇m) transmission
Edit : Här konstateras alltså droppar vilka mäter över 5 micrometer som ej luftburna av WHO, trots att de bevisligen tas upp av de övre luftvägarna.
Bio-aerosol remain suspended in air for long periods of time. Transported by air currents.
Small particles ≤ 5 μm :
# Target may be far away/different rooms.
Bio-aerosol Size and Persistence in the Air :
A droplet of :
100 μm : 10 seconds
40 μm : 1 minute
20 μm : 4 minutes
10 μm : 20 minutes [Upper respiratory]
5-10 μm : 30-45 minutes. [Upper respiratory]
5 μm Droplet nuclei May be inhaled to alveoli [Deeper into lungs]
http://ldh.la.gov/assets/oph/Center-PHCH/Center-CH/infectious-epi/HAI/InfectionsbyAerosolsDropletsHandout.pdf
Bio-aerosol Size Bio-aerosols size and reach into the Respiratory Tract:•
>10 μm in aerodynamic diameter blocked by nasal region.
Between 5 and 10 μm deposit in the upper respiratory system.
≤ 5 μm can reach the alveoli and cause lower respiratory tract infectionBased on size and persistence as an aerosol,
the World Health Organization uses a particle diameter of 5 𝜇m to delineate between •Airborne (≤ 5 𝜇m) •Droplet (> 5 𝜇m) transmission
Edit : Här konstateras alltså droppar vilka mäter över 5 micrometer som ej luftburna av WHO, trots att de bevisligen tas upp av de övre luftvägarna.
Bio-aerosol remain suspended in air for long periods of time. Transported by air currents.
Small particles ≤ 5 μm :
# Target may be far away/different rooms.
Bio-aerosol Size and Persistence in the Air :
A droplet of :
100 μm : 10 seconds
40 μm : 1 minute
20 μm : 4 minutes
10 μm : 20 minutes [Upper respiratory]
5-10 μm : 30-45 minutes. [Upper respiratory]
5 μm Droplet nuclei May be inhaled to alveoli [Deeper into lungs]
En annan lättläst artikel :
Citat:
https://www.nature.com/articles/s41598-019-38825-y
Data from randomized controlled trials of hand hygiene and surgical face masks in households provided evidence that aerosol transmission accounts for half of all transmission events.
A recent study with outpatients who tested positive for influenza A virus demonstrated that 53% and 42% produced aerosol particles containing viable influenza A virus during coughing and exhalation.
A mathematical model of influenza transmission within a household has suggested that the aerosol transmission route may not only be important, but indeed dominant8. Another mathematical model suggests that aerosol transmission is the dominant mode of transmission in long-term epidemics, whereas larger droplets could play a dominant role for short-term epidemics with high attack rates5.
Data from randomized controlled trials of hand hygiene and surgical face masks in households provided evidence that aerosol transmission accounts for half of all transmission events.
A recent study with outpatients who tested positive for influenza A virus demonstrated that 53% and 42% produced aerosol particles containing viable influenza A virus during coughing and exhalation.
A mathematical model of influenza transmission within a household has suggested that the aerosol transmission route may not only be important, but indeed dominant8. Another mathematical model suggests that aerosol transmission is the dominant mode of transmission in long-term epidemics, whereas larger droplets could play a dominant role for short-term epidemics with high attack rates5.
Citat:
Toward Understanding the Risk of Secondary Airborne Infection: Emission of Respirable Pathogens
Mark Nicas , William W. Nazaroff & Alan Hubbard
https://www.tandfonline.com/doi/full/10.1080/15459620590918466
Certain respiratory tract infections are transmitted through air. Coughing and sneezing by an infected person can emit pathogen-containing particles with diameters less than 10 μ m that can reach the alveolar region.
Mark Nicas , William W. Nazaroff & Alan Hubbard
https://www.tandfonline.com/doi/full/10.1080/15459620590918466
Certain respiratory tract infections are transmitted through air. Coughing and sneezing by an infected person can emit pathogen-containing particles with diameters less than 10 μ m that can reach the alveolar region.
Citat:
Characterization of infectious aerosols in health care facilities: An aid to effective engineering controls and preventive strategies
Eugene C. Cole, DrPH
, Carl E. Cook, MS
Durham, North Carolina
https://www.ajicjournal.org/article/S0196-6553(98)70046-X/fulltext#Bioaerosol%20size%20and%20aerodynamics
Inherent in the infection process initiated by the inhalation of infectious droplet nuclei is the area of deposition within the respiratory tract. Such deposition is influenced by hygroscopicity, which causes an increase in the size of inhaled aerosols through moisture take up as they move within the airways. Knight59 estimates that a 1.5 μm hygroscopic particle—a common size in coughs and sneezes—increases to 2.0 μm in diameter when passing through the nose and to 4.0 μm in the saturated air of the nasopharynx and the lung. He further theorizes that the effect of hygroscopicity and the resultant particle size change increase retention in the tertiary bronchioles and alveolar ducts, an effect that may be significant for viral aerosols, which are highly infectious for that part of the lung.
Eugene C. Cole, DrPH
, Carl E. Cook, MS
Durham, North Carolina
https://www.ajicjournal.org/article/S0196-6553(98)70046-X/fulltext#Bioaerosol%20size%20and%20aerodynamics
Inherent in the infection process initiated by the inhalation of infectious droplet nuclei is the area of deposition within the respiratory tract. Such deposition is influenced by hygroscopicity, which causes an increase in the size of inhaled aerosols through moisture take up as they move within the airways. Knight59 estimates that a 1.5 μm hygroscopic particle—a common size in coughs and sneezes—increases to 2.0 μm in diameter when passing through the nose and to 4.0 μm in the saturated air of the nasopharynx and the lung. He further theorizes that the effect of hygroscopicity and the resultant particle size change increase retention in the tertiary bronchioles and alveolar ducts, an effect that may be significant for viral aerosols, which are highly infectious for that part of the lung.
Citat:
Exhaled particles and small airways
B. Bake, P. Larsson, G. Ljungkvist, E. Ljungström & A-C Olin
Respiratory Research volume 20, Article number: 8 Published: 11 January 2019.
https://respiratory-research.biomedcentral.com/articles/10.1186/s12931-019-0970-9
Exhaled air is an aerosol containing endogenously generated droplets. These droplets contain water and nonvolatile material, and “particles” is therefore the physical designation, even though they are liquid droplets. Studies of exhaled particles originally aimed to understand the transmission of airborne infections.
B. Bake, P. Larsson, G. Ljungkvist, E. Ljungström & A-C Olin
Respiratory Research volume 20, Article number: 8 Published: 11 January 2019.
https://respiratory-research.biomedcentral.com/articles/10.1186/s12931-019-0970-9
Exhaled air is an aerosol containing endogenously generated droplets. These droplets contain water and nonvolatile material, and “particles” is therefore the physical designation, even though they are liquid droplets. Studies of exhaled particles originally aimed to understand the transmission of airborne infections.
Citat:
Dynamics of infectious disease transmission by inhalable respiratory droplets
Nikolaos I. Stilianakis1,2,* and Yannis Drossinos1,3
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2894888/
For respiratory infectious diseases, influenza probably being the most prominent example, three different, mutually non-exclusive, main modes of respiratory pathogen transmission have been identified (Tellier 2006; Brankston et al. 2007). The classification used in the medical literature considers ‘contact’, ‘droplet’ and ‘airborne’ transmission. Airborne transmission (also referred to aerosol transmission) occurs via inhalation of small respiratory droplets (also referred to as ‘droplet nuclei’) that are small enough to remain airborne.
Respiratory droplets, all droplets generated by an expiratory event—coughing, sneezing, laughing, talking, breathing , have diameters d that cover a large size range from approximately 0.6 µm to more than 1000 µm. Droplets responsible for transmission by inhalation have also been classified as respirable and inspirable (Nicas & Sun 2006).
Respirable droplets remain airborne sufficiently long to provide a mechanism for airborne transmission. They contribute to infection transmission by inhalation as they may be inhaled immediately after generation (e.g. during the first breath) instead of direct deposition onto the upper respiratory tract.
Nikolaos I. Stilianakis1,2,* and Yannis Drossinos1,3
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2894888/
For respiratory infectious diseases, influenza probably being the most prominent example, three different, mutually non-exclusive, main modes of respiratory pathogen transmission have been identified (Tellier 2006; Brankston et al. 2007). The classification used in the medical literature considers ‘contact’, ‘droplet’ and ‘airborne’ transmission. Airborne transmission (also referred to aerosol transmission) occurs via inhalation of small respiratory droplets (also referred to as ‘droplet nuclei’) that are small enough to remain airborne.
Respiratory droplets, all droplets generated by an expiratory event—coughing, sneezing, laughing, talking, breathing , have diameters d that cover a large size range from approximately 0.6 µm to more than 1000 µm. Droplets responsible for transmission by inhalation have also been classified as respirable and inspirable (Nicas & Sun 2006).
Respirable droplets remain airborne sufficiently long to provide a mechanism for airborne transmission. They contribute to infection transmission by inhalation as they may be inhaled immediately after generation (e.g. during the first breath) instead of direct deposition onto the upper respiratory tract.
Citat:
https://backend.orbit.dtu.dk/ws/files/147140728/Ai_et_al_2018_Indoor_Air.pdf
The majority of these droplets evaporate fast to half of their initial size and become droplet nuclei.20In particular,the evaporation process completes instantaneously for smalldroplets with an initial size of less than 20 μm.20Some previous studiesshow that droplets fromhuman respirationactivities are mostly less than 5-10μm in diameter.22,27-34This size rangeis considered to be the lower cut-off size for droplets and is used to differentiate between airborne and droplet transmission(the latter occurs over short distances by direct transfer between occupants of relatively large respiratory droplets). Owing to various influential factors, including particularly the air humidity35, different cut-off sizes were suggested in different contexts.3,36-37Lindsley et al.38measured influenza virus in droplet nuclei generated by a coughing patient and reported that 42% of detected viruseswere foundin droplet nuclei < 1 μm, 23% in droplet nuclei of 1-4 μm and 35% in droplet nuclei > 4 μm. Airborne droplet nucleicould remain suspendedin air for a prolonged periodand be transported over an extended distance by indoor airflows.
https://backend.orbit.dtu.dk/ws/files/147140728/Ai_et_al_2018_Indoor_Air.pdf
The majority of these droplets evaporate fast to half of their initial size and become droplet nuclei.20In particular,the evaporation process completes instantaneously for smalldroplets with an initial size of less than 20 μm.20Some previous studiesshow that droplets fromhuman respirationactivities are mostly less than 5-10μm in diameter.22,27-34This size rangeis considered to be the lower cut-off size for droplets and is used to differentiate between airborne and droplet transmission(the latter occurs over short distances by direct transfer between occupants of relatively large respiratory droplets). Owing to various influential factors, including particularly the air humidity35, different cut-off sizes were suggested in different contexts.3,36-37Lindsley et al.38measured influenza virus in droplet nuclei generated by a coughing patient and reported that 42% of detected viruseswere foundin droplet nuclei < 1 μm, 23% in droplet nuclei of 1-4 μm and 35% in droplet nuclei > 4 μm. Airborne droplet nucleicould remain suspendedin air for a prolonged periodand be transported over an extended distance by indoor airflows.
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Senast redigerad av snuttis 2020-04-01 kl. 20:37.
Senast redigerad av snuttis 2020-04-01 kl. 20:37.
