The source of the outbreak appears to have been the Artibonite river and its canals. People use the canal water to drink, bathe, launder clothes and wash food.

Improvements in roads and the large-scale construction of canals allowed food to be transported from areas of plenty to areas of scarcity.

For the last six years I have occupied a small room, giving on to one of the side canals of Venice, and having no one about me but a deaf old woman, who makes my bed and attends to my food;