Thursday, May 14, 2020

Very Brief Blog: More About Masks: Atul Gawande in New Yorker

In Los Angeles, on May 14, we woke up to news that we are required to wear masks when outdoors.  Prior, masks had been required when shopping (groceries, drugstores) but recommended outside when near people.   

Masks for the public in streets and parks been controversial nationally, with strong feelings on both sides.   This week there is a review by Atul Gawande in New Yorker (May 13, here.  I think this is open access if you click through enough subscription offers.)   

I have been suspicious of classic surgical-type masks (typically blue paper), because of the large spaces they usually leave at the sides.   Gawande notes these are actually specially-designed electrostatic fibers meant to try virus at high rates.   (I'm not sure if that grade of paper technology is also found in non-certified blue paper masks sold to the public, though).   

Gawande also quotes a preprint 8 page "evidence review" (not peer reviewed) by Howard et al. on mask value, here.  Howard et al. include a multi color chart which I think is actually relatively simple data modeling.    They assume that R=2.4 (transmittals per infected individual; bottom left corner), and they project transmittal rates if 0-100% of people wear masks which are 0-100% effective.   

For example, if 100% of people wore masks that were 50% effective, R=1.2, and similarly if 50% of people wore masks that were 100% effective.   
(This modeling and limit-modeling is not real data, but it can be helpful.  For example, I don't know what Anthony Fauci weighs, yet I can also be 100% sure it is more than 110 pounds and less than 180 pounds.   It would be great to know if the requirements for masks changed infection somewhere between [+20% to -20%], or alternately, somewhere between [-20% to -60%].)
Preprint Typesetting Watch

As far as I remember, a couple months ago, preprint articles at BioRxiv or MedRxiv were almost always very bare-bones affairs.   

A week ago I noticed a preprint (Kai et al) that was upping the typesetting quality of the preprint game (here).    

For my eye, the Howard et al. pre-print on mask efficiency pulls the preprint game another step higher, with quite elaborate typesetting.   See a screen shot of Howard et al., page 1, below.

Increasingly elaborate typesetting of un-reviewed preprints