Re: risk zones

[Christian Huitema <[e-mail]>]

On 3/6/2020 7:45 AM, Rich Kulawiec wrote:

> On Fri, Mar 06, 2020 at 09:58:24AM -0500, Phillip Hallam-Baker wrote:
>> That has absolutely no effect on the spread in the West where we have taken
>> none of those measures. 
> Related to this point, I fumbled my way through a scholarly discussion
> of COVID-19 as best as a layman can, and came away with this point: with
> a disease that has a long incubation period, the reported cases tell us
> where it has *been*, not where it *is*.  I'm terribly oversimplifying,
> of course, but this is consistent with the observations being reported
> by WHO et.al.   And it means, among other things, that delayed reactions
> may be much too late.


Most people on this list have no medical background, but many understand
routing and graphs. This is indeed a classic problem of propagation in a
graph, the graph of social contacts. People may get infected if they
have contact with someone who is. Once infected, they are capable of
infecting others for some time. The denser the graph, the faster the
infection spreads. Large gatherings create very dense graphs, and that's
why they are problematic.

-- Christian Huitema