What are causes of yellow fever?

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Yellow fever is caused by a virus that is spread by the Aedes aegypti mosquito. These mosquitoes thrive in and near human habitations where they breed in even the cleanest water. Most cases of yellow fever occur in sub-Saharan Africa and tropical South America.

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The above answer is excellent. I would simply like to add further detail.

Yellow fever is transmitted to humans through daytime-biting mosquitoes-mainly the Aedes aegypti and Haemagogus species, that are infected with the yellow fever virus.

In the jungles and tropical rainforests, these mosquitoes feed on monkeys that are infected with the disease, and then bite humans working or traveling within the forest.

Occasionally, infected travelers from rural areas introduce the virus to cities, where the dense population makes it easy for indigenous mosquitoes to carry the disease from person-to-person. This urban cycle of transmission can cause large and explosive yellow fever epidemics. Yellow fever is constantly present, or endemic, in many tropical areas of South America and Africa.

First answer by Jasminemayer. Last edit by Palazzo. Contributor trust: 52 [recommend contributorrecommended]. Question popularity: 2 [recommend question].