That's Il Principe :)

maybe a civ v version of health could almost be its own expansion-like mod?

- making bison, citrus, and cocoa grant health
- permanent buffs to health and caps to unhealthiness from techs
- great scientists now reduce unhealthiness when used. if a plague is happening the great scientist gives bonus science and ends the plague
- cheap buildings that sacrifice health for low upkeep high yields
- specialists take increased negative effects of unhealthiness to offset their reduced food upkeep
- units lose combat strength if they are damaged in the territory of an unhealthy enemy city, and units in a city's territory decrease its health, your civ becomes immune once penicillin is researched
- end game project: genome project - if you have had a great scientist cure a plague you can do the genome project and choose to either be able to permanently increase citizen health every turn, or to be able to create bioweapon wmds