This is the first Cholera in Haiti for a hundred years according to the BBC.
According to my health NGO buddy around 150 people die from regular intestinal infections, especially bacterial infections each week normally in Haiti.
The river in St Marc flooded mixing with sewage (turds) and this is the main source of water for cooking, washing and for some, drinking.
Again, according to the BBC, the situation although not a direct result of the earthquake is being exacerbated by lots of extra people living in the St Marc / Artibonite region having left Port au Prince because of the earth quake. So the earthquake could be seen as a proximate cause, if you like.
If you wash your hands and eat only canned food, well cooked food and boiled and disinfected water and remember not to eat any turds then you should be OK.
Nobody has to die of Cholera as it is easily treatable.
Allegedly there are 100,000 IV treatments available - not enough obviously.
And 30,000 vaccination doses available - I will give you three guesses who gets those
Most Haitian country folk see upset stomachs and mild diarrhea as a way of life - not a nice thing to say but it is true - so these people did not think anything out of the ordinary was happening until it was too late. That is what caused the initial spike in the death toll.
The cases in Port au Prince apparently were people who got infected further north and traveled to Port au Prince - thus Port au Prince is not a new infection center - according to the BBC.
As a precaution, I personally am restricting myself to certain distilled spirits, fine imported tonic water, ice that I make myself and lemon (yes the yellow ones) that I bought before the outbreak - oh, and cigarettes for my vitamins.