The disease originated in Africa and spread to the Americas starting in the 17th century with the European trafficking of enslaved Africans from sub-Saharan Africa. This is believed to be due to fewer people being immune, more people living in cities, people moving frequently, and changing climate increasing the habitat for mosquitoes. Since the 1980s, the number of cases of yellow fever has been increasing. It is common in tropical areas of the continents of South America and Africa, but not in Asia. Nearly a billion people live in an area of the world where the disease is common. Approximately 90 percent of an estimated 200,000 cases of yellow fever per year occur in Africa. In 2013, yellow fever was estimated to have caused 130,000 severe infections and 78,000 deaths in Africa. Death occurs in up to half of those who get severe disease.

Once a person is infected, management is symptomatic no specific measures are effective against the virus. In areas where yellow fever is common, early diagnosis of cases and immunization of large parts of the population are important to prevent outbreaks.

Other efforts to prevent infection include reducing the population of the transmitting mosquitoes. Ī safe and effective vaccine against yellow fever exists, and some countries require vaccinations for travelers. To confirm a suspected case, blood-sample testing with a polymerase chain reaction is required. The disease may be difficult to tell apart from other illnesses, especially in the early stages. The virus is an RNA virus of the genus Flavivirus.

In cities, it is spread primarily by Aedes aegypti, a type of mosquito found throughout the tropics and subtropics. It infects humans, other primates, and several types of mosquitoes. The disease is caused by the yellow fever virus and is spread by the bite of an infected mosquito. If this occurs, the risk of bleeding and kidney problems is increased. In about 15% of people, within a day of improving the fever comes back, abdominal pain occurs, and liver damage begins causing yellow skin. Symptoms typically improve within five days. In most cases, symptoms include fever, chills, loss of appetite, nausea, muscle pains – particularly in the back – and headaches. Yellow fever is a viral disease of typically short duration. ~130,000 severe cases in Africa alone (2013) Yellow jack, yellow plague, bronze john Ī TEM micrograph of yellow fever virus (234,000× magnification)įever, chills, muscle pain, headache, yellow skin

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