Yellow fever | |
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Other names | Yellow jack, yellow plague,[1] bronze john[2] |
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A TEM micrograph of Yellow fever virus (234,000× magnification) | |
Specialty | Infectious disease |
Symptoms | Fever, chills, muscle pain, headache, yellow skin[3] |
Complications | Liver failure, bleeding[3] |
Usual onset | 3–6 days post exposure[3] |
Duration | 3–4 days[3] |
Causes | Yellow fever virus spread by mosquitoes[3] |
Diagnostic method | Blood test[4] |
Prevention | Yellow fever vaccine[3] |
Treatment | Supportive care[3] |
Frequency | ≈130,000 severe cases in Africa alone (2013)[3][5] |
Deaths | ≈78,000 in Africa alone (2013)[3][5] |
Yellow fever is a viral disease of typically short duration.[3] In most cases, symptoms include fever, chills, loss of appetite, nausea, muscle pains—particularly in the back—and headaches.[3] Symptoms typically improve within five days.[3] In about 15% of people, within a day of improving the fever comes back, abdominal pain occurs, and liver damage begins causing yellow skin.[3][6] If this occurs, the risk of bleeding and kidney problems is increased.[3][7]
The disease is caused by the yellow fever virus and is spread by the bite of an infected mosquito.[3][8] It infects humans, other primates,[9] and several types of mosquitoes.[3] In cities, it is spread primarily by Aedes aegypti, a type of mosquito found throughout the tropics and subtropics.[3] The virus is an RNA virus of the genus Flavivirus.[10][11] The disease may be difficult to tell apart from other illnesses, especially in the early stages.[3] To confirm a suspected case, blood-sample testing with a polymerase chain reaction is required.[4]
A safe and effective vaccine against yellow fever exists, and some countries require vaccinations for travelers.[3] Other efforts to prevent infection include reducing the population of the transmitting mosquitoes.[3] In areas where yellow fever is common, early diagnosis of cases and immunization of large parts of the population are important to prevent outbreaks.[3] Once a person is infected, management is symptomatic; no specific measures are effective against the virus.[3] Death occurs in up to half of those who get severe disease.[3][12]
In 2013, yellow fever was estimated to have caused 130,000 severe infections and 78,000 deaths in Africa.[3][5] Approximately 90 percent of an estimated 200,000 cases of yellow fever per year occur in Africa.[13] Nearly a billion people live in an area of the world where the disease is common.[3] It is common in tropical areas of the continents of South America and Africa,[14] but not in Asia.[3][15] Since the 1980s, the number of cases of yellow fever has been increasing.[3][16] 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.[3]
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.[1][17] Since the 17th century, several major outbreaks of the disease have occurred in the Americas, Africa, and Europe.[1] In the 18th and 19th centuries, yellow fever was considered one of the most dangerous infectious diseases; numerous epidemics swept through major cities of the US and in other parts of the world.[1]
In 1927, the yellow fever virus became the first human virus to be isolated.[10][18]
The yellow fever virus was isolated in 1927
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