Vi som är kritiska till Sveriges handhavande av pandemin

Nej, för principen är ungefär lika enkel. En låst dörr gör det svårare att komma in, ett munskydd gör det svårare för droppsmittan att komma ut, genom att skapa en barriär. Rätt basic ju, i grund och botten :\

Men okej. Låt oss säga att det är en gissning. Visst. Allting som inte ger 100% garanterat skydd mot en grej är en gissning. Men vad är då mantrat om "falsk trygghet"? Bevis - annars också en gissning. Isf, vad gör att FHMs gissningar väger tyngre?

Transmission of COVID-19 virus by droplets and aerosols: A critical review on the unresolved dichotomy

2020 Sep; 1

Abstract

The practice of social distancing and wearing masks has been popular worldwide in combating the contraction of COVID-19. Undeniably, although such practices help control the COVID-19 pandemic to a greater extent, the complete control of virus-laden droplet and aerosol transmission by such practices is poorly understood. This review paper intends to outline the literature concerning the transmission of virus-laden droplets and aerosols in different environmental settings and demonstrates the behavior of droplets and aerosols resulted from a cough-jet of an infected person in various confined spaces. The case studies that have come out in different countries have, with prima facie evidence, manifested that the airborne transmission plays a profound role in contracting susceptible hosts. The infection propensities in confined spaces (airplane, passenger car, and healthcare center) by the transmission of droplets and aerosols under varying ventilation conditions were discussed.

Interestingly, the nosocomial transmission by airborne SARS-CoV-2 virus-laden aerosols in healthcare facilities may be plausible. Hence, clearly defined, science-based administrative, clinical, and physical measures are of paramount importance to eradicate the COVID-19 pandemic from the world.

2.?Sources and mechanisms of generating and transmitting droplets and aerosols

Although the direct transmission from infected person/s is the primary source of aerosols and droplets, other scenarios such as medical procedures, surgeries (Judson and Munster, 2019), fast-running tap water and toilet flushes (Morawska, 2006) also generate aerosols contaminated with infectious pathogens. The most common types of viruses causing infections in the respiratory tract through aerosol transmission are influenza viruses, rhinoviruses, coronaviruses, respiratory syncytial viruses (RSVs), and parainfluenza viruses (Morawska, 2006). Tellier (2009) has postulated three modes in which the influenza virus can be transmitted: aerosol transmission, droplet transmission, and self-inoculation of the nasal mucosa by contaminated hands. Another classification is presented by Judson and Munster (2019), which is often referred to as the term of ?airborne transmission? to describe the disease spread by small droplet aerosols and droplet nuclei, while the term ?droplet transmission? to describe infection by large droplet aerosols. The term ?airborne transmission? defined by Morawska (2006) is quite similar to the same apprehended by Judson and Munster (2019). Besides, the direct contact and fomite transmission produced by aerosol-generating medical procedures (AGMPs) can also be considered as potential transmission pathways (Judson and Munster, 2019).

Droplet transmission occurs by the direct spray of large droplets onto conjunctiva or mucous membranes of a susceptible host when an infected patient sneezes, talks, or coughs. In the meantime, direct physical touch between an infected individual and susceptible host and indirect contact with infectious secretions on fomites can cause the contact transmission (Boone and Gerba, 2007; Brankston et al., 2007; Nicas et al., 2005; Tellier, 2006).

It is a well-known fact that COVID-19 is transmitted by human-to-human contact; hence, contagious. One of the predominant mechanisms for COVID-19 to be contagious is self-inoculation from contaminated fomites. Self-inoculation could occur by poor hand hygiene (Kwok et al., 2015) or by not following the common disease-controlling etiquettes. The viral transmission because of the frequent touches of contaminated fomites was found to be a source of the disease. Consequently, many researchers have paid attention to the airborne transmission directly by virus-laden droplets and aerosols. However, the novelty of this viral outbreak limits the prima facie evidence to determine the potential transmission routes, and thus, it is assumed that SARS-CoV-2 also spreads as the other human coronaviruses (CDC, 2020a).

[...]

3.?Size distribution, time taken, and distances transmitted by aerosols and droplets produced by infected people

The SARS-CoV-2 is often said to be transmitted through droplets generated when a symptomatic person coughs, sneezes, talks, or exhales (Morawska and Cao, 2020). Some of these droplets are too heavy to remain in the air, and rather fall on nearby floors or surfaces. Fomites collect droplets contaminated with SARS-CoV-2, and touching of such surfaces by a susceptible host would get infected. However, some droplets, when ejected from an infected person, convert to aerosol particles (also known as bioaerosols) with relatively smaller aerodynamic diameters and, consequently, become airborne (Morawska, 2006). Such virus-laden aerosol particles are capable of infecting people who inhale such particles, thereby spreading the disease. Further, there have been several transport phenomena where larger droplets become smaller through evaporation so that such smaller particles are called droplet nuclei. Such aerosol particles with the encapsulation of viruses could be termed as bioaerosols or droplet nuclei; hence, the term ?aerosol?, ?bioaerosol?, and ?droplet nuclei? is used in this paper interchangeably. The scenarios in respect of the generation of droplets and aerosol, particularly in the indoor environment, have not been adequately understood, and thus, insights into the plausible mechanisms are worthy of being explored. Duguid (1945), for the first time, has explored the characteristics of droplets and aerosol from human expiratory activities with chest infections, and such information is presented in Table 1 . Duguid (1945) has observed that 95% of particles were often smaller than 100 ?m, and the majority were between 4 and 8 ?m. The findings corroborated that breathing and exhalation originated from the nose have shed up to a few hundreds of droplets of which some were aerosols. In contrast, talking, coughing, and sneezing have produced more aerosols than droplets (Table 1).

www.ncbi.nlm.nih.gov/pmc/articles/PMC7293495/

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Nej, för principen är ungefär lika enkel. En låst dörr gör det svårare att komma in, ett munskydd gör det svårare för droppsmittan att komma ut, genom att skapa en barriär. Rätt basic ju, i grund och botten :\

Men okej. Låt oss säga att det är en gissning. Visst. Allting som inte ger 100% garanterat skydd mot en grej är en gissning. Men vad är då mantrat om "falsk trygghet"? Bevis - annars också en gissning. Isf, vad gör att FHMs gissningar väger tyngre?

2.?Sources and mechanisms of generating and transmitting droplets and aerosols

Although the direct transmission from infected person/s is the primary source of aerosols and droplets, other scenarios such as medical procedures, surgeries (Judson and Munster, 2019), fast-running tap water and toilet flushes (Morawska, 2006) also generate aerosols contaminated with infectious pathogens. The most common types of viruses causing infections in the respiratory tract through aerosol transmission are influenza viruses, rhinoviruses, coronaviruses, respiratory syncytial viruses (RSVs), and parainfluenza viruses (Morawska, 2006). Tellier (2009) has postulated three modes in which the influenza virus can be transmitted: aerosol transmission, droplet transmission, and self-inoculation of the nasal mucosa by contaminated hands. Another classification is presented by Judson and Munster (2019), which is often referred to as the term of ?airborne transmission? to describe the disease spread by small droplet aerosols and droplet nuclei, while the term ?droplet transmission? to describe infection by large droplet aerosols. The term ?airborne transmission? defined by Morawska (2006) is quite similar to the same apprehended by Judson and Munster (2019). Besides, the direct contact and fomite transmission produced by aerosol-generating medical procedures (AGMPs) can also be considered as potential transmission pathways (Judson and Munster, 2019).

Droplet transmission occurs by the direct spray of large droplets onto conjunctiva or mucous membranes of a susceptible host when an infected patient sneezes, talks, or coughs. In the meantime, direct physical touch between an infected individual and susceptible host and indirect contact with infectious secretions on fomites can cause the contact transmission (Boone and Gerba, 2007; Brankston et al., 2007; Nicas et al., 2005; Tellier, 2006).

Om du läser lite noggrannare så ser du att jag skriver att det rör sig om luftburna aerosoler, inte luftburen smitta som är en annan klassifikation. 

Underliga uttryck, min semantik, läser upp?
Jag skriver bara att aerosolerna är luftburna, så inte milsvid skillnad från luftburen smitta, trots att det är något annat. 
Vi alla, trevligt att du gör dig till talesman för alla andra
Tack för dina råd!

Det där var bra! En medicinboll är luftburen enligt hennes sätt att tänka. Så är det....

Kanon - då har vi en terminologi vi kan använda i tråden fortsättningsvis

Droppsmitta
Aerosolsmitta
Luftburen smitta

Det är allmän kännedom att droppar kan färdas genom luften, inte lika långt som Ricky Bruch kastar medicinboll dock.
Det är allmän kännedom  att aerosoler kan färdas genom luften, oklart om de kommer lika långt som Ricky Brush kastar medicinboll
Det är allmän kännedom att luftburen smitta kan färdas genom luften, den luftburna smittan kommer minst lika långt som Rickys kast med medicinboll

Faktaruta ? aerosoler

Källa???

Markerade delen är egentligen fel. Visserligen verkar man inte vara helt överens, men det är uppenbar droppsmitta genom aerosoler.

Okej, det verkar finnas några som definiera luftburen smitta lite annorlunda, men det är bara förvirrande. :)  Men det sista som du markerade - det innebär att några partiklar av covid-19-aerosoler kan vara tillräckligt små för att de ska kunna flyga iväg som luftburen smitta? Inte bra i så fall. Då är det förstås fråga om det är så pass mycket att det verkligen spelar en roll i smittspridningen.

Droppar är vätskeform, är det viruspartiklar i droppar är det droppsmitta, kommer dropparna flygandes är det droppsmitta, eftersom det är droppar som bär på partiklarna och dessa droppar tar med sig partiklarna när de landar.
Är partiklarna blandad med t.e.x luft som är en gas är det gaslösning/luftlösning. Gaslösningen, gasen+partiklarna en aerosol, det är vad man inom aerosolteknologin kallar för aerosol smitta och det är luftburen smitta eftersom det är luften som bär på partiklarna, dessa partiklar kan "hänga" kvar i luften, de dras med luftströmmar.

Vi andas ut vattenånga, vattenånga är en gas, är det partiklar i vattenångan är det en aerosol.
Hostar man droppar kan dropparna torka till aerosol.

" Då är det förstås fråga om det är så pass mycket att det verkligen spelar en roll i smittspridningen. "
Det är väl aerosolen som kan dras ned till alveolerna så det låter inte som en höjdare på nära håll.
Masker blir inte lika effektiva.