It is an infectious disease that is spread by a parasite in sandflies that use domestic dogs as hosts.[68] The emergence of leishmaniasis in Brazil, specifically the Northeast state of Ceará, is theorized to date back to the Great Drought of the 19th century Brazil. The Grande Seca of 1877 to 1878 led to the mass migration of approximately 55 thousand Brazilians from Ceará to the Amazon for employment on rubber plantations.[69] The disease is easily and mostly transmitted on plantations in which the people live and work.[70]