## Pages

##### (AMS Bumper Sticker)

 Web math-frolic.blogspot.com

## Thursday, October 16, 2014

### A Mathematical Parable... and Ebola

I've shortened and simplified this post considerably. It wasn't even intended for the regular math-literate readership here who almost certainly know the classic story of grains of wheat accumulating on a 64-square chessboard; but rather for their possible math-phobic friends who need a more vivid understanding of the potential exponential nature of numbers-growth, in lieu of the Ebola story unfolding.

Ever since the virus spread (completely unlike prior decades) beyond the villages it was usually confined to, and especially since its spread beyond the shores of West Africa, some of us have had a more cautionary, skeptical view than the CDC's confident stance, because of the simple mathematics of the situation (combined with the fact that NO amount of medical protocols/regulations realistically offers 100% prevention of spread, given that humans who must carry out such protocols are imperfect, suffer lapses, make mistakes, are forgetful or tired or ill-trained, or in a hurry, etc.etc. (And that's no fault of theirs, that's just being normal humans, instead of machines). While the 70+ contacts of the Dallas Liberian victim might seem a manageable number, 300, 500, or 1000 potential contacts/exposures will not be easily manageable. (The fact that the virus doesn't spread through the air is lucky for us, but by no means precludes widespread infection.). Enough said:

[p.s., in a recent release the World Health Organization warned that before the end of this year there could be as many as 10,000 new cases of Ebola in Western Africa alone every week -- I'd be a bit surprised if that happened... but that IS the point of the above video, it could happen that fast.] Somewhere between calm and panic there is an appropriate state of alarm and alertness that the American public needs to find, to be prepared for the major disruption this epidemic, and consequent public health measures, could cause society. "Be prepared" is often a more trenchant maxim than "stay calm." Or, to put it a different way, the "precautionary principle" again takes hold (better to be overly precautious, than not precautious enough).

As an aside, in the short term, I'll say that my own confidence lies, not in our ability to necessarily control the spread of this disease, but rather in our ability to attain early diagnosis and more effective treatment for it, cutting the current 70% fatality rate significantly (but that too certainly isn't assured).