User:Mr. Ibrahem/Yellow fever
Medical condition / From Wikipedia, the free encyclopedia
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]
Yellow fever | |
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Other names | Yellow jack, yellow plague,[1] bronze john[2] |
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 | ~127,000 severe cases (2013)[3] |
Deaths | 5,100 (2015)[5] |
The disease is caused by yellow fever virus and is spread by the bite of an infected female mosquito.[3] It infects only humans, other primates, 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.[7] 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 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 infected, management is symptomatic with no specific measures effective against the virus.[3] Death occurs in up to half of those who get severe disease.[3][8]
In 2013, yellow fever resulted in about 127,000 severe infections and 45,000 deaths,[3] with nearly 90 percent of these occurring in African nations.[4] 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, but not in Asia.[3][9] Since the 1980s, the number of cases of yellow fever has been increasing.[3][10] 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 South America with the slave trade in the 17th century.[1] 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 seen as one of the most dangerous infectious diseases.[1] In 1927, yellow fever virus was the first human virus isolated.[7][11]