CDC *boggling*

[Goose]

And now the CDC says that masks _do_ protect the wearer.  

https://www.cnn.com/2020/11/10/health/ma...index.html

Seems like it's taking us 8+ months to get to where Taiwan and other Asian countries were. (unfortunately, I don't mean cases)

I hope their messaging doesn't change again in a few days.

I must admit I am somewhat disappointed that the CDC does not cite clear reasons for changes it makes in policy. If you read the release, there are lots of "might" and "may" words in there. This is fine, but it is a lot better to present the evidence upon which the change is based. If you don't do that, the question becomes "Why is this advice any better than the previous advice?".

[oregontim]

And now the CDC says that masks _do_ protect the wearer.  

https://www.cnn.com/2020/11/10/health/ma...index.html

Seems like it's taking us 8+ months to get to where Taiwan and other Asian countries were. (unfortunately, I don't mean cases)

I hope their messaging doesn't change again in a few days.

I must admit I am somewhat disappointed that the CDC does not cite clear reasons for changes it makes in policy. If you read the release, there are lots of "might" and "may" words in there. This is fine, but it is a lot better to present the evidence upon which the change is based. If you don't do that, the question becomes "Why is this advice any better than the previous advice?".

Goose, interesting point. I agree with you. But I'm a bit torn, because with science in general, and particularly with regards to Covid-19, "might" and "may" are probably more accurate than being certain. As I get older, the more I see uncertainty as a sign of intelligence. So here I am full of OTOH thoughts.

[Mick]

Goose, interesting point. I agree with you. But I'm a bit torn, because with science in general, and particularly with regards to Covid-19, "might" and "may" are probably more accurate than being certain. As I get older, the more I see uncertainty as a sign of intelligence. So here I am full of OTOH thoughts.

I must be a g.d. genius, then...

[oregontim]

Goose, interesting point. I agree with you. But I'm a bit torn, because with science in general, and particularly with regards to Covid-19, "might" and "may" are probably more accurate than being certain. As I get older, the more I see uncertainty as a sign of intelligence. So here I am full of OTOH thoughts.

I must be a g.d. genius, then...

+1 ... funny is good. We need funny these days.

[Goose]

I must admit I am somewhat disappointed that the CDC does not cite clear reasons for changes it makes in policy. If you read the release, there are lots of "might" and "may" words in there. This is fine, but it is a lot better to present the evidence upon which the change is based. If you don't do that, the question becomes "Why is this advice any better than the previous advice?".

Goose, interesting point. I agree with you. But I'm a bit torn, because with science in general, and particularly with regards to Covid-19, "might" and "may" are probably more accurate than being certain. As I get older, the more I see uncertainty as a sign of intelligence. So here I am full of OTOH thoughts.

I totally agree that uncertainty may be the most accurate description of the situation. Sometimes, that is just reality. Unfortunately, it isn't considered politically correct to admit what yo don't know. If the CDC would just say "Our opinion has changed because after evaluating the situation we believe it probable that mask operate somewhat bilaterally. We do not have conclusive proof of this, but there is a reasonable argument that it is so." I think that represents reality, and people can understand the position. I think that works much better than just changing the position and not saying anything about why.

[magnus]

New guidance from the CDC which pretty much reinforces what some have posted here. 

https://www.cnn.com/2020/11/20/health/cd...index.html

Symptomatic individuals cause less than half the spread.

Most infectious before symptoms and usually at 5 days. 

And loudly talking, singing,  or heavy breathing expels more virus.

[magnus]

CDC has updated their exposure quarantine guidelines. 

https://www.cnn.com/world/live-news/coro...3a776aec71

Quarantine can end after 10 days without a Covid-19 test if the person reported no symptoms, or after seven days with a negative test result if the person has reported no symptoms

[magnus]

More detail (which i haven't had a chance to read)

https://www.cdc.gov/coronavirus/2019-nco...ntine.html

[M T]

More detail (which i haven't had a chance to read)

https://www.cdc.gov/coronavirus/2019-nco...ntine.html

So, the CDC still says
  "CDC currently recommends a quarantine period of 14 days."

But they're offering that some might choose to release people from quarantine at transmission risk levels (estimated by the model used in this one paper) of as high as 5.5% (CI: 0.1% to 11.9%).   So, the risk levels suggest that maybe 1 in 20 people (or even 1 in 9) released would cause transmission (not just having COVID).   That's far higher than the 0.1% (0.0 to 3.0%) transmission risk of the 14 day quarantine.

Well, that's one way to say "Its ok with me if you injure someone else, but don't blame me".

Wow, do they make risk assessments like this for other risks?

[oldalum]

how is "transmission risk" defined in these graphs? spending 15 minutes within 6 feet without a mask? or what?

[BostonCard]

This is a good question; I wonder if it is empiric (i.e., not based on a specific level of contact, but rather based on what people actually do, which of course is a range).

BC