Post #907: Social distancing rule + quarantine rule = insanity.

Posted on December 4, 2020

Source:  Japan Ministry of Health.

I’m not confused because I’m stupid.  I’m confused because I’m paying attention to what they’re actually saying.

Let’s see if you can find the inconsistency in current CDC advice.

The social distancing rule:  The CDC continues to focus on “social distancing” as the primary defense against spread of COVID-19.  That means staying at least 6′ apart.  The theory there is that people who cough or sneeze emit “droplets” containing infectious material.  And if you stay at least that far away, you are unlikely to be hit by somebody’s droplets.


The quarantine rule:  If you’ve been exposed to COVID-19, you need to quarantine yourself for 14 days.  (Or fewer — see below).  You need to do this whether or not you have any symptoms at all.  Because asymptomatic or pre-symptomatic individuals can spread COVID-19 quite effectively.  And you could be spreading disease without knowing it.

Does it seem like I have that right, more or less?  The CDC added masks to that social distancing rule, but only after the fact. Only as kind of an oddly-worded add-on recommendation.  And the CDC has recently added some grudging mention of aerosols (tiny drops that can float on the air) in addition to droplet transmission.

By and large, I think the paragraphs above capture what the CDC has told the American public.  Maintain social distancing to avoid the droplets produced when people cough or sneeze.  And quarantine yourself for 14 days if exposed, even if you have no symptoms.  And wear a mask, too.

Now let me get down to the insanity part, by putting those two rules together.  You must maintain social distancing, because when people cough or sneeze, they emit droplets that can travel up to 6′ and transmit infection.  And if you’ve been exposed, you must quarantine even if you have no symptoms and are not coughing or sneezing, because you might transmit infection.

This mish-mosh of internally-inconsistent guidance is an historical artifact.  It’s the result of the way the CDC policies have evolved over time.  In particular, it’s the result of the CDC being unwilling to admit that aerosol transmission matters.  (Aerosols being tiny particles, smaller than “droplets”, that can float on the air well beyond the standard six-foot social distancing barrier.)  And only making grudging and piecemeal changes to its guidance, that kind-of, sort-of, recognized the importance of aerosol transmission.

You can see the apex of that process in Post #822, when the CDC issued and then immediately revoked guidance with clear discussion of aerosols. You can review the long, winding road to get to that guidance, in Post #820. The CDC did eventually produce guidance so larded with weasel-wording on this key issue as to be more-or-less unusable.  You can see that discussion in Post #850.

They key problem here is that if aerosol transmission matters, then social distancing is not an adequate way to prevent spread of COVID-19.  For the simple reason that aerosols routinely spread beyond six feet.  And so, for the CDC to go all-in on aerosol transmission is for them to admit that they offered really fundamentally bad advice to the American public.  And so, they can’t really admit it.  And we end up with the current internally-inconsistent and piecemeal advice from the CDC.

This has a couple of immediate impacts on health care policy.

First, many U.S. states continue to base their own recommendations on the original CDC “social distancing is the main line of defense” message.  And so the effect of the mixed and unclear CDC guidance has been to promulgate state mask mandates that make mask wearing an alternative to social distancing, only if social distancing cannot be maintained. 

Iowa, for example, passed a mask mandated in the middle of November (Post #893).  It requires individuals to wear masks, indoors, in a public place, only if they are unable to maintain 6′ social distancing, and are unable to maintain it for more than 15 minutes.  So in Iowa, you’re required to wear a mask only where social distancing fails for an extended period of time. 

And so, if aerosol transmission matters, and social distancing alone is an inadequate public health measure, the upshot of all of this confusion from CDC is the creation of state-level rules that sanction dangerous behavior.  That Iowa mask mandate tells the people of Iowa that not wearing a mask is good sanitary practice, as long as you aren’t within six feet of an individual for more than 15 minutes.

So Iowa, following the main CDC message, has now told its citizens that it’s perfectly fine to (e.g.) meet somebody for a cup of coffee and have a 10-mintue face-to-face chat.  With no masks.  Because masks are only an needed if you’re going to spend 15 minutes or more in that situation.

Second, more recently, the CDC seems to have finally woken up to the fact that people who don’t feel ill aren’t doing the recommended 14 days of quarantine when exposed to COVID-19.  So they’ve decided to shorten the quarantine period for those with no symptoms.  The theory being, I guess, that the increased compliance with a shorter quarantine more than offsets the handful of individuals who will still be infectious at the end of that shorter quarantine period.

The entire change is aimed at asymptomatic individuals.  If you’re coughing or sneezing, or have any other symptoms, the new rules do not apply.  But if you’ve been exposed to COVID-19 and have no symptoms, you only have to quarantine for ten days (without testing) or seven days (if you get a negative COVID-19 test).   You can read the actual CDC recommendation here.

If the CDC ever gets to wondering why people who didn’t feel sick didn’t stick to a 14-day quarantine, I think it should start by looking at its own advice and messaging.  They start out by pressing that sneezing-coughing-droplets-distancing message.  Then they turn right around and try to tell people that, well, we were just kidding about that whole sneezing and coughing thing.  That doesn’t really matter, after all.  Just do your 14 days regardless.

And, unsurprisingly, a lot of people seem to be ignoring that second message.  So now the CDC is trying to patch that up a bit, by recommending a shorter quarantine for asymptomatic individuals.

But what they really need to do is rethink this from square one.  In light of what we now know, if you could rewrite the CDC guidance from scratch, what should it say?  At the minimum, if you want asymptomatic individuals to take this seriously, you’d start by dropping the whole sneezing-coughing-droplets party line.  Go straight to droplet or aerosol transmission.  Note that social distancing alone is inadequate.

And replace the current patched-together guidance with a single, unified, easy-to-grasp message.  Something akin to what the Japanese have been telling their population from Day 1, shown at the top of this posting.  Compare that, to whatever the current CDC guidance is, and you’ll see that our guidance just does not measure up.