It was one room (with a divider), two patients, two collectors.But from how many rooms did they manage to cultivate virus from sampling the air? One, or two?
It looks to me like they did not get any live virus from Patient 2, who was negative. The live virus was from Patient 1, the active case.It was one room (with a divider), two patients, two collectors.
There was one collector and one patient on either side of the room divider.
Apparently, the divider was not entirely effective at blocking the virus, because patient 2's collector was still picking up SARS-Cov-2 (at 16 particles per liter) after patient 2 was discharged.
That's the only case so far - is it a special case? Restaurants have opened in Singapore with safe distancing for quite some time now, with so far no rise in the rate of infections. People are unmasked while eating.1) indoors, the most critical thing is near universal mask wearing because aerosols can last an hour or more and distance is minimal protection. Evidence: detailed analysis of restaurant transmission, where adjacent tables as well as tables 20+ feet away connected by air flow patterns were the ones affected. Distance is the next most important factor. Mask wearing has to be near universal because the weaknesses of non ND95 masks are minimized if all parties wear them (at least covering nose and mouth).*
I tend to agree. But there is one bizarre case that is hard to explain. Two people attended the same church at totally different times (when I've heard the data presented in a seminar, it seems that security camera footage supports that the two people did not meet), but sat in the same seat. It has been suggested that the first person infected the second. Look at the description of "Cluster A" in https://www.cdc.gov/mmwr/volumes/69/wr/mm6914e1.htm.On the other hand, I am highly skeptical of surface transmission. Someone sneezes near a surface and it gets contaminated. Virus starts degrading at a steady rate. Someone touches the surface getting, say, 1/10 the viral load in the air near the surface at the time of the sneeze. Then, they scratch the outside of their nose, inhaling at the same time, say another tenfold reduction in viral load. Thus, compared to inhalation of aerosols near where someone recently sneezed, you have 100 fold reduction in viral load for the multistep touch transmission. Note, no amount of viral load on your hands will matter unless you touch your nose or mouth (possibly, but unverified, eyes) before washing your hands or waiting for the virus to degrade. Epidemiologists have so far documented no case whatsoever of coronovirus transmission primarily by surface touching. And of spread by droplet/aerosol inhalation, indoor cases outnumber outdoors by 50-1.
This paper supports that the restaurant case you mentioned was likely due to aerosol transmission. However, it does not support what you say about "irrespective of distance".However, epidemiologists are now more and more agreeing with the idea that for indoors protection when others are not wearing masks, the only adequate protection is an ND95 mask, irrespective of distance
There is no reason that you need to be in the same room at the same time to become exposed to a SARS-Cov-2 aerosol. The particles are smaller than tobacco smoke and will remain in undisturbed air for hours. If there is pedestrian traffic, it will not settle out. The limiting factor becomes the survival of the virus in that environment - which is related to temperature, humidity, and sunlight.I tend to agree. But there is one bizarre case that is hard to explain. Two people attended the same church at totally different times (when I've heard the data presented in a seminar, it seems that security camera footage supports that the two people did not meet), but sat in the same seat. It has been suggested that the first person infected the second. Look at the description of "Cluster A" in https://www.cdc.gov/mmwr/volumes/69/wr/mm6914e1.htm.
Contradiction in terms. I would argue that she is NOT "quite intelligent".I have a friend who is an anti-vaxxer. She's quite intelligent, but there's no amount of scientific evidence that will persuade her that vaccines work.
Yes, the Western decision to claim masks weren't important because there was a shortage was one of the worst health policy decisions ever made. Even independent of evidence one could track down, especially regarding the similar SARS and MERS viruses, it was logically inconsistent to say that N95 masks were critical to protect healthcare workers, but masks were not important for the public. Claims were made that imperfect masks wouldn't help the wearer because they couldn't stop viral size particles, while they protected others because they could stop droplets. This is a logical absurdity - if you catch it most commonly by droplets, then the mask that reduces droplets from one direction reduces them from the other as well. Failure to stop virus size particles is wholly irrelevant. This led me, back at the beginning of March, to trust nothing except my own investigations and experiments; the CDC and WHO were quite obviously not presenting objective science.IMO it is wrong to cast the mask issue as one of knowledge versus ignorance. It is primarily a matter of trust.
Just a few months ago, science said that the public should not wear masks. Plenty of evidence about masks preventing spread existed back then, mostly in Asian publications. It is rational to suspect that either science deliberately lied to the public about masks because there were not enough N95 masks to go around, or that western science succumbed to the not-invented-here syndrome. Either way, trust in science and scientists took a big hit.
Public reluctance to believe scientists can sometimes be attributed to bad behavior of the scientists rather than the ignorance of the public. If scientists just stuck to publishing their scientific results and were silent on public policy, they would have more respect. The more often scientists say "Hear me and obey, because I am a scientist." the worse the problem.
No comment on the CDC whose advice I have not followed in detail. For the WHO, I would say the public messaging was badly explained to the point of being misleading (which does erode public trust), rather than incorrect (ie. it was based on objective science), as it is true that if there is a mask shortage, medical masks should be prioritized for health care workers and people with respiratory symptoms, while the general community should rely on other measures such as safe distancing (in January the WHO guidance was safe distancing from people with respiratory symptoms, in April the WHO guidance was updated to have safe distancing in the community; the April guidance also provided considerations for masking when safe distancing could not be maintained, eg. in public transport).This led me, back at the beginning of March, to trust nothing except my own investigations and experiments; the CDC and WHO were quite obviously not presenting objective science.