Well, the windsurfing and foiling has been good - we've been on the water 5 of the last 7 days, with three sessions that I'd label as "excellent". But we stayed home today, and I discovered a few things that called for another COVID-19 related blog post. Here we go:
Instead, I want to look at an example about how medical "experts" just "know" that COVID-19 is transmitted "almost exclusively" or "always" through "large droplets", even when there is plenty of evidence staring right at them that this is NOT the whole explanations.
The issue started when I followed up on a couple of links in a study titled "Avoiding COVID-19: Aerosol Guidelines". References 65 to 68 in this article link to three different events where a large number of choir members got infected during choir practice or performances. I had written about the choir in Washington State already, but the others were new to me. They describe two choirs in the Netherlands, in Amsterdam and the town of Heerde, where 40% respectively 75% of the choir members contracted COVID-19. I then did a quick search for similar incidents in Germany, and found three similar choir events: in Berlin, Hohenberg, and Stade.
What really got to me was the statements by a German professor, Christian Kähler of the Military University, Munich, as reported by The Guardian. He did some experiments to see how far he could see air movements from the mouths when singing; found that the air moves less than 2 feet; and concluded:
"However, we also found out that singing is quite safe. It was not the cause of the outbreaks of Covid-19 at these concerts."That statement goes against a lot of evidence, but it is easy to understand where he is coming from when we look at another statement he made:
"I have been studying how droplets and aerosols behave for decades and I was very doubtful that musicians and singers were spreading the virus."So, he was very skeptical, and set out to prove his point. Never mind that you actually cannot prove a negative - his study was deeply flawed because he only looked at air movement - he did not even look at aerosols! In fact, his own institute's web page that reports the experiment results explicitly states that not only that good ventilation is essential to avoid infections, but that the air should be flowing vertically, from inlets on the floor to outlets in the ceiling.
So Kähler concludes that all the infections that happened during choir practice must have happened when people where in close proximity - less than a meter, according to his own data. But the very short forward air movement that he takes as evidence that "singing is safe" would not even reach the person in front of a singer! So practically all transmissions would have to happen during breaks, when participants get coffee and mingle. The one or perhaps two initially infected people would then have to sneeze or cough at dozens of others in very close proximity. The "direct droplet" infection route even requires that some of the sneeze droplets hit the other persons mouth, nose, or eyes directly .. dozens of times here. Never mind that sneezing is quite rare with COVID-19, and not even listed as an official symptom!
Old "expert" guys like Kähler who simple refuse to consider new evidence, and rather direct their research efforts only to prove that what they always have said must be right, are very dangerous. They remind me very much at the doctor who treated my father when his dementia got bad. The doctor was the top expert for Alzheimer's in Germany, so he diagnosed my father with Alzheimer. He gave him psychotropic drugs, which perhaps would have been ok if the diagnosis had been correct - but they put my father into a catatonic state. Weeks later, other doctors correctly diagnosed my father with the second-most common dementia, Lewy body dementia (LBD); one characteristic is that LBD patients react very badly to psychotropic drugs.
Medical doctors who re-iterate the "common knowledge" that COVID-19 is transmitted by "large droplets" are at least as dangerous as my father's doctor. My father eventually recovered from most of the side effects, but in several of the choirs listed above, one or more members or their spouses died from COVID-19. It is very likely that the primary mode of transmission was long-distance transmission through aerosolized virus particles. There is plenty of science that supports this - studies that have shown that patients emit virus when talking; studies that show the particles can remain airborne for extended times, and that the virus remains infections in airborne particles for hours; studies that show that loud speaking and singing can release thousands to tens of thousands virus-containing droplets; and studies that show that direct inhalation is actually the most effective way of getting infected (check the summaries and links in this article for details, or various posts on my COVID-19 blog).
The science is clear: there is overwhelming evidence that aerosol transmissions can cause COVID-19 infections. Even with aerosol transmissions, staying 6 feet away from others dramatically reduces the chance of infection - but if you are indoors with many others for a longer period of time, and there's a lot of talking or singing going on, that's not enough, and a substantial chance of infection remains.
Some of the basic underlying science has been known for years. Some of the COVID-19 specific information has only become available in recent weeks. Unfortunately, a lot of the information at the "official" sites like the CDC, WHO, and Germany's RKI still focus mostly on "droplets made when an infected person coughs, sneezes or talks", and elaborate that "these droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs."
One often-heard argument against updating these guidelines is that "there is no proof of aerosol transmission". That is mostly true (although there is plenty of circumstantial evidence) - but there is also no firm evidence of droplet transmission. If anything, the available evidence indicates that indirect droplet transmission ("fomite" transmission) only plays a minor role. But besides a few experts like Kähler who are unable to change their minds "just because" of new evidence, there's another factor that makes this unlikely: concerns about aerosol transmissions may keep people out of restaurants and other indoor spaces, and thus work against "restarting the economy". But so will increasing case numbers that are partly due to misinformation!
