I didn’t see any mention of Laotians being affected. Was this restricted only to tourists at a bar, or did only the tourist deaths matter for the new cycle?

They actually still do bloodletting, and even use leeches to do it.

https://www.calculusmadeeasy.org/4.html

This exact explanation is in the book: https://calculusmadeeasy.org/4.html

I also studied chemical engineering, and throughout high school and university that was exactly it. Calculus was a kind of magic, and you just had to learn all the spells.

With this book I finally understood why the derivative of x^2 is 2x.