Bergman, Leslie. "History of colonization in South America". Stellenbosch University, Stellenbosch, South Africa. Archived from the original on 24 May 2010. Retrieved 25 October 2009.
Stellenbosch, South Africa's Department of Modern Foreign Languages's Historical Background article South America says: "Yellow fever was an uninvited "guest" brought to the Americas on the slave ships from West Africa. Yellow fever is caused by a virus spread by the bite of a species of mosquito native to West Africa, the aedes aegypti. This mosquito was accidentally carried across the Atlantic in water barrels on the slave ships. Yellow fever struck communities from New York to Rio de Janeiro, but aedes aegypti flourished in tropical zones. The mosquito, and with it yellow fever, spread rapidly throughout the Amazon River valley. The disease was so lethal to Europeans, who had little immunity to it, that mass settlement of the Amazon region was not possible until present times."
Bergman, Leslie. "History of colonization in South America". Stellenbosch University, Stellenbosch, South Africa. Archived from the original on 24 May 2010. Retrieved 25 October 2009.
Stellenbosch, South Africa's Department of Modern Foreign Languages's Historical Background article South America says: "Yellow fever was an uninvited "guest" brought to the Americas on the slave ships from West Africa. Yellow fever is caused by a virus spread by the bite of a species of mosquito native to West Africa, the aedes aegypti. This mosquito was accidentally carried across the Atlantic in water barrels on the slave ships. Yellow fever struck communities from New York to Rio de Janeiro, but aedes aegypti flourished in tropical zones. The mosquito, and with it yellow fever, spread rapidly throughout the Amazon River valley. The disease was so lethal to Europeans, who had little immunity to it, that mass settlement of the Amazon region was not possible until present times."