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The experiment that proved airborne disease transmission

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Re: The experiment that proved airborne disease transmission

#21

Post by nradov »

_Microft wrote: post #5
redis_mlc wrote: post #2

[flagged]

Why bother to disinfect when you can ventilate? Air with pathogens out, fresh air without pathogens in. (Regarding herd immunity: you're aware that at the current rate of 55000 people per day, it would take 10 years to infect 60% of 320 million people? Nothing to say of the countless casualties that you would get in the process.)

Since eradicating the virus has become impossible, most national governments are currently pursuing a herd immunity strategy by default. They're just doing it at slightly different rates.

In the USA the current daily rate of confirmed new cases is about 43000, not 55000. However there are a large number of "dark matter" cases not counted in official statistics. About 40% of infections are asymptomatic, and many more are paucisymptomatic. Most of those patients never get tested.

Re: The experiment that proved airborne disease transmission

#22

Post by function_seven »

_Microft wrote: post #5
redis_mlc wrote: post #2

[flagged]

Why bother to disinfect when you can ventilate? Air with pathogens out, fresh air without pathogens in. (Regarding herd immunity: you're aware that at the current rate of 55000 people per day, it would take 10 years to infect 60% of 320 million people? Nothing to say of the countless casualties that you would get in the process.)

Probably cheaper to slot a component into your HVAC than it is to re-engineer it to draw outside hot air, cool it, and still keep interiors at a comfortable level. (Reverse for winter)

My house has a fantastic filter along with a UV system as well. When I bought the house I thought it was overkill, but now I’m quite happy it’s there.

Re: The experiment that proved airborne disease transmission

#23

Post by lifeisstillgood »

UV-C lights that irradiate an air duct is literally the most surprising (and in retrospect obvious) thing I learnt today.

Is this something a household HVAC could be upgraded to. Do HNers in areas that have air con think it's a "yeah people will want that" idea?

Re: The experiment that proved airborne disease transmission

#24

Post by TheSpiceIsLife »

lifeisstillgood wrote: post #23

UV-C lights that irradiate an air duct is literally the most surprising (and in retrospect obvious) thing I learnt today. Is this something a household HVAC could be upgraded to. Do HNers in areas that have air con think it's a "yeah people will want that" idea?

What magnitude of irradiance is required?

If the required power is,say, 500w continues, or more, that's going to get quite expensive to run.

For example, where I live running a 500w device 24/7 is going to add an extra $1100 a year to the power bill.

Re: The experiment that proved airborne disease transmission

#25

Post by _Microft »

nradov wrote: post #21
_Microft wrote: post #5

Earlier quoted context omitted.

Why bother to disinfect when you can ventilate? Air with pathogens out, fresh air without pathogens in. (Regarding herd immunity: you're aware that at the current rate of 55000 people per day, it would take 10 years to infect 60% of 320 million people? Nothing to say of the countless casualties that you would get in the process.)

Since eradicating the virus has become impossible, most national governments are currently pursuing a herd immunity strategy by default. They're just doing it at slightly different rates. In the USA the current daily rate of confirmed new cases is about 43000, not 55000. However there are a large number of "dark matter" cases not counted in official statistics. About 40% of infections are asymptomatic, and many more…

What countries are actually following a strategy to reach herd immunity by having "enough" people fall ill and hopefully recover (having "recovered" does not preclude persisting damages btw!)?

Most countries are rather waiting for a vaccine to become available and try to minimize the number of sick and dead in the meantime without interfering with economy too much.

(54.4k was number of newly confirmed cases on friday 10/2 by the John-Hopkins University btw. I'm aware that the US has inadequate testing [0] and that the real number is going to be a lot higher than this.

[0] https://ourworldindata.org/coronavirus-testing#the-positive-... )

Re: The experiment that proved airborne disease transmission

#26

Post by sokoloff »

shalmanese wrote: post #14
dboreham wrote: post #11

Earlier quoted context omitted.

Also supposedly if a disease is declared airborne then hospitals have to adopt various isolation measures beyond just N95 that are very costly. This may be the reason the powers that be won't announce airborne transmission until after the pandemic is over.

We make fun of medieval medicine but look at this shit! We're pretending that saying some magic words has an effect on a physical reality of disease spread! Who says that saying its airborne "has" to mean that certain procedures have to be adopted? That's not a rule of the universe, it's a rule that humans came up with and agreed upon and humans have the power to fix. We distilled down a set of physical principles in…

Unless you say something like “look it’s airborne but that fact shall not be admissible into any future lawsuits on any topic” (and have certainty that that will stand up to review), I’m not sure you can fully equate to the current “it’s not been declared to be airborne transmissible.”

Re: The experiment that proved airborne disease transmission

#27

Post by jchw »

shalmanese wrote: post #14
dboreham wrote: post #11

Earlier quoted context omitted.

Also supposedly if a disease is declared airborne then hospitals have to adopt various isolation measures beyond just N95 that are very costly. This may be the reason the powers that be won't announce airborne transmission until after the pandemic is over.

We make fun of medieval medicine but look at this shit! We're pretending that saying some magic words has an effect on a physical reality of disease spread! Who says that saying its airborne "has" to mean that certain procedures have to be adopted? That's not a rule of the universe, it's a rule that humans came up with and agreed upon and humans have the power to fix. We distilled down a set of physical principles in…

While I understand the frustration, the reality is we shouldn’t be making fun of either. Just because the end result of something is inarguably “stupid” does not mean that any of the things that went into it are “stupid.” To do the Hacker News thing and make a bad analogy to computer science topics in a totally irrelevant thread, this is how I view a lot of stuff people complain about these days (think JavaScript, or Electron apps.) Real life is hard.

To be a bit more concrete, consider the following: if you have a system where people are not encouraged to follow the rules as written, they will work against the spirit of what is written as well as what is actually written. If you have a system where people are discouraged from not following the rules, they may still engage in things that do not follow the spirit or written rules, but there is some accountability. But you can also try to work around what’s written to follow the intent as well, and I think that is where you get weird, counterintuitive, “stupid” results that can still “make sense” (as opposed to clearly corrupt cases where it is “stupid” and also does not make sense.)

I think people, especially literal minded as many here are, prefer concrete rules. But the knock-on effect is that its not easy to simply proclaim they’re made up any time it’s inconvenient, and it really shouldn’t be. Perhaps, in fact in my opinion, definitely, the “escape hatches“ for when rules don’t work out practically are broken, but I still do prefer having rigid standards, especially for health.

Hopefully, although it is probably not going to happen, organizations can have some postmortem-style reflections on what went wrong, so that hopefully next time we can be better prepared. History loves repeating though, so, you know.

Re: The experiment that proved airborne disease transmission

#28

Post by ajsnigrutin »

lifeisstillgood wrote: post #23

UV-C lights that irradiate an air duct is literally the most surprising (and in retrospect obvious) thing I learnt today. Is this something a household HVAC could be upgraded to. Do HNers in areas that have air con think it's a "yeah people will want that" idea?

I always wondered just how much UV-C do you need to effectively kill the virus (power vs duct diameter and air speed).... because, instead of traditional masks, you could take a small fan, blow air into a pipe with a UV-C bulb inside, and pump the sterilized air to the human... basically something like this: https://www.youtube.com/watch?v=fzGrh2io9Ds&app=desktop

Re: The experiment that proved airborne disease transmission

#29

Post by [deleted] »

lucb1e wrote: post #12

TL;DR: the actual experiment: > they constructed an air-tight closed ventilation system that connected a six-room tuberculosis ward to an exposure chamber with 150 guinea pigs. (Among rodent animal models, only guinea pigs could cough and sneeze, making them ideal for studying how respiratory diseases spread.) The guinea pigs were exposed to the infected air over a four-year period. A second group of 150 guinea pigs…

[deleted]

Re: The experiment that proved airborne disease transmission

#30

Post by nradov »

_Microft wrote: post #25
nradov wrote: post #21

Earlier quoted context omitted.

Since eradicating the virus has become impossible, most national governments are currently pursuing a herd immunity strategy by default. They're just doing it at slightly different rates. In the USA the current daily rate of confirmed new cases is about 43000, not 55000. However there are a large number of "dark matter" cases not counted in official statistics. About 40% of infections are asymptomatic, and many more…

What countries are actually following a strategy to reach herd immunity by having "enough" people fall ill and hopefully recover (having "recovered" does not preclude persisting damages btw!)? Most countries are rather waiting for a vaccine to become available and try to minimize the number of sick and dead in the meantime without interfering with economy too much. (54.4k was number of newly confirmed cases on friday…

Only New Zealand, Taiwan, Vietnam, and maybe a couple other countries are actively avoiding herd immunity. Regardless of their public statements, other countries aren't actually trying to minimize the number of sick and dead. The public health measures in place are generally insufficient to contain the pandemic, so I predict that many areas will reach a significant level of herd immunity before a safe and effective vaccine is widely available. We won't know whether that prediction is accurate until about a year from now.
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