Yellow fever is probably the most lethal of all the arboviruses. It is caused by a flavivirus that is transmitted by the Haemogogus mosquitoes and several different species of the Aedes mosquito. Although it has occurred in areas extending from Mexico to Argentina, most cases of yellow fever are in Africa and Central and South. .
The symptoms of yellow fever appear 3 - 6 days after exposure, and include fever, nausea, shivers, vomiting, flushed face, constipation, stomach discomfort, loss of appetite, headache, muscle pains, backache, restlessness, and irritability. A remission period follows these symptoms, and mild cases of yellow fever end here. 15% of the victims will have a severe case of yellow fever. A remission of several hours or days will follow the first stage. The fever recurs, the victim develops the classic symptoms of yellow fever, including jaundice (yellowed skin and eyes) and black, coffee-ground vomit, hemorrhages, and kidney function deteriorates. Half of the victims that enter the second stage die within 10-14 days while the remainder recover without significant organ damage.
Yellow fever epidemics have hit European seaports and many American towns and cities leaving behind devastating results. It probably originated in Africa and was transported via shipping to port cities in the New World, where from 1668 to 1893 it erupted in 135 major epidemics, leaving behind panic, fear, and widespread death. New Orleans, Louisiana, Memphis, and Philadelphia were among the hardest hit. In 1793, 1 of every 10 Philadelphians died. In New Orleans, during a major outbreak in 1853, there were 29,000 cases with over 8,000 deaths. One of the worst American epidemics occurred in 1878 involving 132 towns, 75,000 cases, and 16,000 deaths. Eventually, scientific research began to shed light on the origins of yellow fever and its link to mosquitoes. In 1881, Dr. Carlos Finlay, was the first to suggest that a mosquito transmitted the disease.