Thursday, August 6, 2020

Quitting Covid: tests at home?

 Well, friends, here we are, with the utterly predictable farce of a federal non- response causing over 160,000 US deaths so far (and counting), the only nation on earth unable (because unwilling) to get out in front of this virus.  

Let's just sit with that number for a minute.  That's 1000 people a day, roughly the equivalent of 4 airliner crashes.  EVERY DAY, for 2 years.  It's the equivalent of a 9/11 event every third day:  53 9/11s. It's twice as many deaths than military losses in the entire Vietnam war.  

We know what works, because other countries have shown us.    Avoid what the Japanese call the 3-Cs:  conversation in crowded, confined spaces.  Practice the 3 Ws:  wear a mask, wash your hands, watch your distance.  I would add to that, stay outside. Assume any person outside your immediate household is infected.  

Over and over, we see evidence that this virus spreads inside, by aerosols  (not so much by touch, though washing your hands frequently is a good idea).  Your mask reduces your ability to spread aerosols.  Your mask protects me.  My mask protects you.  Recent studies have suggested that my mask may also reduce my exposure sufficiently to ameliorate the course of disease (that is , inhaling less virus means a lower severity of disease).  We'll have to see if this is the case.

Really.  Just wear the damn mask.  It's a helluva lot less invasive than a ventilator and is an act of community love.

One of our stellar failures is in testing.  We aren't testing enough people fast enough to do any good. (If you don't get your results for 1 week, you've exposed how many people in that time?  Including your family?)  So a Harvard virologists says, why not use less accurate tests that are fast, and cheap enough to use at home every day or two?  That would do better than we are doing now, where we know we are missing tons of positive cases.

Here's why that theory works.  In this first figure, you can see roughly where we are now. Assume 10% of the population is infected.  We are testing only a small fraction of that population and say 10% are positive among those (that's actually high, it's a little less than that).  So we caught that person and isolated them , but the others we missed went on to infect more people (second panel).

Now, think of testing everyone with a test that's only 50% accurate:  meaning it would miss 50% of cases on the first pass.  (I haven't put the stars on everyone for reasons of space).  Even if you only did it once, We would STILL reduce the number of cases (compare the right panel of this one, to the one above).  But here's the thing.  It's not one-and-done.  When you tested again the next day, or two days later, you'd have another chance to find those remaining positives, which could prevent those additional infections.

If you could test a person every other day for $1 each time, with an immediate response, you would very quickly be able to slow this down. 

This is the United States. We used to put men on the moon--you know, actual rocket science.  We have entrepreneurs and experts and the best scientists in the world.  Why aren't we listening to them?

Instead, public health expert Dr Fauci and his family are getting death threats


Other discussion of COVID on this blog here.