My village of about 350 was short on laborers for my new expansion, so I accepted 30 nomads in the town hall. Almost immediately, there was a cholera outbreak. I was not worried, as I'd dealt with diseases successfully before, and I had two hospitals with physicians and plenty of herbs. However the disease spread very quickly and eventually killed off my population.
I am wondering about the mechanics of diseases - logic would dictate they spread as they do in life, through proximity between villagers. Is the key to treat diseased individuals immediately and hope they did not come in to contact with anyone? Are some diseases more potent, deadly, or contagious than others, or is the difference only in the name and they are mechanically identical? Are villagers able to be contagious before they are marked as diseased or are they marked immediately upon contact? Do disease events only come up when nomads arrive?