Yellow fever

Yellow fever virus under microscope

Yellow fever probably originated in Africa. The first major outbreak in the Americas was in 1648 in Yucatan,  Mexico. The virus was brought to south and central America by ships in the 1500s. The virus is transmitted though female mosquitoes found in tropical and sub tropical climates. In the 1790s there were over 5 major outbreaks in New york, Boston, and Philadelphia that killed over 200,000 people. Many wealthier people evacuated the cities and fled to the country side leaving the poor and the sick behind.
    Yellow fever is a Flavivirus, like ALL other Flaviviruses there is no cure for yellow fever once you get it, although there is an affective vacination you can get. Yellow fever has causes 30,000 deaths a year, mostly in Africa, and South America. The WHO (the world health organization run by the U.N) has called yellow fever a re-emerging disease (since the 1980s the number of cases has been increasing)