Date of this Version
Essential Travel Medicine, First Edition. pp. 75
Yellow fever (YF) virus is transmitted to humans primarily through the bite of an infected Aedes or Haemagogus sp. mosquito. The virus is present in sub-Saharan Africa and tropical South America, where it is endemic and intermittently epidemic . The World Health Organization (WHO) estimates that 200,000 cases of YF, including 30,000 deaths, occur annually worldwide.
YF virus has three transmission cycles: sylvatic (jungle), intermediate (savannah), and urban . Most YF disease in humans is due to sylvatic or intermediate transmission cycles. However, urban YF occurs periodically in Africa and sporadically in the Americas.