At the beginning there was 4 different routes were considered: fecal-oral route, touch-hand-face, droplets in the air, airborne viruses. Fecal-oral route seems to either nonexistent or incredibly small. Airborne (aerosol) risk has been considered very small.
Two main routes are touch-hand-face and droplets in the air. It seems that droplets are the main route (60-70% of infections) rest come from touching things. Social distancing. 2m indoors and hand washing seems to work.
If there is aerosol transmission it seems to be much smaller percentage than two other transmission mechanisms.
Claiming that aerosol vs droplet transmission is artificial distinction is incorrect. Droplets fall down relatively fast and don't linger in the air 10s of minutes like aerosol. Aerosol transmission is more dependent on moisture in the air, they linger longer in dry air. We should see strong seasonal and climate forcing in transmission rates.
Simulations of indoor airflow that show the difference between aerosol and droplet transmissions:
(caution: just inhaling viruses is not enough to cause infection, you need to inhale a dose that is large enough to cause infection)
I don't know how you square discounting aerosol transmission with super spreading events where one person infects dozens of people in less than an hour.
Infecting dozens in a hour sounds like droplet transmission. Especially when the events usually happened when people were signing etc. People shed droplets when they exhale and speak. Singing is much worse.
Aerosol transmission could infect several hundreds if it was significant transmission route.
This article feels like it’s months old or from an alternate universe. We “may” need masks indoors? I’m very confused what is being communicated here. It sounds like a bunch of experts fussing over the finer points of established theory without considering real data about this particular virus. Presumably because they don’t have enough data, but then the focus ought to be on collecting more, not arguing over theory.
The title while technically correct stokes fear more than anything else. The article goes into depth on how “airborne” is not terribly different than what we know now about aerosols hanging in the air. Most people will read the title and react at too large of a scale, while the only real insight should be that in crowded indoor places with poor ventilation (offices, restaurants), you may be able to get infected even when socially distancing.
That is much more reasonable and solvable. Airborne is a overused Hollywood term that makes most people think it floats on the wind and infects you anywhere, anytime.
Some microbes really do float in the wind like that. But apparently viruses tend to get destroyed by sunlight or desiccated fairly easily. Bacteria are more complex, and become world travellers.
Prof Dr Cicero Coimbra showed in an interview a graph that makes you think: with 18 ng/ml vitamin D levels 100% of patients with covid-19 die and with 34 ng/ml 100% survive with a line in between: so the less vitamin D, the higher the risk to die. He has a protocol to give a single high dose of vitamin D and all patients survive. The interview is in Portuguese and the graph has English labels: https://youtu.be/l_nKoLY60lY?t=911
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[ 3.6 ms ] story [ 44.8 ms ] threadTwo main routes are touch-hand-face and droplets in the air. It seems that droplets are the main route (60-70% of infections) rest come from touching things. Social distancing. 2m indoors and hand washing seems to work.
If there is aerosol transmission it seems to be much smaller percentage than two other transmission mechanisms.
Claiming that aerosol vs droplet transmission is artificial distinction is incorrect. Droplets fall down relatively fast and don't linger in the air 10s of minutes like aerosol. Aerosol transmission is more dependent on moisture in the air, they linger longer in dry air. We should see strong seasonal and climate forcing in transmission rates.
Simulations of indoor airflow that show the difference between aerosol and droplet transmissions:
(caution: just inhaling viruses is not enough to cause infection, you need to inhale a dose that is large enough to cause infection)
https://www.aalto.fi/en/news/modelling-confirms-isolating-th...
VTT simulation with only droplets with and without mask:
https://www.youtube.com/watch?v=1YWuD4jdjLc
https://www.youtube.com/watch?v=I-apLuN7sZc
Sounds like cover your ass nitpicking to me.
Aerosol transmission could infect several hundreds if it was significant transmission route.
Medical study: 455 persons exposed to a person with Covid19, non of the 455 persons became sick by the virus. Conclusion: very low infectivity https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7219423/
That is much more reasonable and solvable. Airborne is a overused Hollywood term that makes most people think it floats on the wind and infects you anywhere, anytime.
https://www.smithsonianmag.com/science-nature/living-bacteri...