Doctors without Borders in the US). They are the main organization on the ground helping people According to their website 84,500 people suffering from cholera, or 57 percent all cases reported nationwide, have been treated in MSF or MSF-supported structures.
Also on the website is a link to an interesting article from the Guardian newspaper, Haiti: where aid failed, which asks a very important question:
Haiti should be an unlikely backdrop for the latest failure of the humanitarian relief system. The country is small and accessible and, following last January's earthquake, it hosts one of the largest and best-funded international aid deployments in the world. An estimated 12,000 non-governmental organisations are there. Why then, have at least 2,500 people died of cholera, a disease that's easily treated and controlled?