Yellow fever is caused by yellow fever virus, an enveloped RNA virus 40–50 nm in width, the type species and namesake of the family Flaviviridae. It was the first illness shown to be transmissible by filtered human serum and transmitted by mosquitoes, by Walter Reed around 1900.https://en.wikipedia.org/wiki/Yellow_fever
The yellow fever virus is found in tropical and subtropical areas of Africa and South America. The virus is spread to people by the bite of an infected mosquito. Yellow fever is a very rare cause of illness in U.S. travelers. Illness ranges from a fever with aches and pains to severe liver disease with bleeding and yellowing skin (jaundice).
Sep 22, 2020 · Yellow fever is a viral infection spread by a particular type of mosquito. The infection is most common in areas of Africa and South America, affecting travelers to and residents of those areas. In mild cases, yellow fever causes a fever, headache, nausea and vomiting.
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Once contracted, the yellow fever virus incubates in the body for 3 to 6 days. Many people do not experience symptoms, but when these do occur, the most common are fever, muscle pain with prominent backache, headache, loss of appetite, and nausea or vomiting. In most cases, symptoms disappear after 3 to 4 days.
Yellow fever is difficult to diagnose, especially during the early stages. A more severe case can be confused with severe malaria, leptospirosis, viral hepatitis (especially fulminant forms), other haemorrhagic fevers, infection with other flaviviruses (such as dengue haemorrhagic fever), and poisoning. Polymerase chain reaction (PCR) testing in blood and urine can sometimes detect the virus in early stages of the disease. In later stages, testing to identify antibodies is needed (ELISA and P...
Forty seven countries in Africa (34) and Central and South America (13) are either endemic for, or have regions that are endemic for, yellow fever. A modelling study based on African data sources estimated the burden of yellow fever during 2013 was 84 000–170 000 severe cases and 29 000–60 000 deaths. Occasionally travellers who visit yellow fever endemic countries may bring the disease to countries free from yellow fever. In order to prevent such importation of the disease, many countries re...
The yellow fever virus is an arbovirus of the flavivirus genus and is transmitted by mosquitoes, belonging to the Aedes and Haemogogus species. The different mosquito species live in different habitats - some breed around houses (domestic), others in the jungle (wild), and some in both habitats (semi-domestic). There are 3 types of transmission cycles: 1. Sylvatic (or jungle) yellow fever: In tropical rainforests, monkeys, which are the primary reservoir of yellow fever, are bitten by wild mo...
Good and early supportive treatment in hospitals improves survival rates. There is currently no specific anti-viral drug for yellow fever but specific care to treat dehydration, liver and kidney failure, and fever improves outcomes. Associated bacterial infections can be treated with antibiotics.
Vaccination is the most important means of preventing yellow fever. The yellow fever vaccine is safe, affordable and a single dose provides life-long protection against yellow fever disease. A booster dose of yellow fever vaccine is not needed.Several vaccination strategies are used to prevent yellow fever disease and transmission: routine infant immunization; mass vaccination campaigns designed to increase coverage in countries at risk; and vaccination of travellers going to yellow fever end...
In 2016, two linked urban yellow fever outbreaks – in Luanda (Angola) and Kinshasa (Democratic Republic of the Congo), with wider international exportation from Angola to other countries, including China – have shown that yellow fever poses a serious global threat requiring new strategic thinking. The Eliminate Yellow Fever Epidemics (EYE) Strategy was developed to respond to the increased threat of yellow fever urban outbreaks with international spread. Steered by WHO, UNICEF, and Gavi, the...
Yellow fever is caused by yellow fever virus, an enveloped RNA virus 40–50 nm in width, the type species and namesake of the family Flaviviridae. It was the first illness shown to be transmissible by filtered human serum and transmitted by mosquitoes, by Walter Reed around 1900.
May 21, 2019 · Yellow fever is a serious, potentially deadly flu-like disease spread by mosquitoes. It’s characterized by a high fever and jaundice. Jaundice is yellowing of the skin and eyes, which is why this...
- Colleen M. Story
Yellow fever is a viral infection transmitted by a bite from infected mosquitoes most commonly found in parts of South America and Africa. When transmitted to humans, the yellow fever virus can damage the liver and other internal organs and be potentially fatal.
The World Health Organization estimates there are 200,000 cases of yellow fever worldwide each year, resulting in 30,000 deaths. Yellow fever appears to be on the rise internationally, due to a decreased immunity to infection among local populations, deforestation, climate change, and high-density urbanization.
The CDC has identified 44 counties with a risk of yellow fever transmission, many of them with tropical climates. While the actual number of yellow fever cases among U.S. and European travelers to these at-risk countries is low, vaccination is advised for most international travelers to these countries, because yellow fever has no cure and can be deadly. Because there is no cure for yellow fever, prevention is critical. The yellow fever vaccine is advised for adults and children over age 9 months who are traveling to or living in countries with a known risk of yellow fever. Certain countries in Africa and Latin America with the highest risk of exposure to yellow fever now require proof of yellow fever vaccination before allowing you to travel there. Travel medicine clinics and state or local health departments usually offer the vaccine, which needs to be repeated every 10 years for people traveling to high-risk areas. These approved vaccination centers can also provide you with the International Certificate of Vaccination that you'll need to enter certain at-risk countries. Yellow fever vaccination is not advised for everyone. The vaccine can cause serious adverse effects in certain people. Efforts are under way to develop a killed vaccine that will be safer. Talk with your doctor before getting the vaccine if you: Keep in mind that vaccination has two goals: to protect the health of individual travelers coming into high-risk regions and to protect the public health of countries by preventing the import of yellow fever into their region. If you're exempt from vaccination for medical reasons, you may need to provide proof of exemption for entry into some countries. Vaccination is the most important measure you should take when traveling to areas where exposure to the yellow fever virus is possible. No other measure is more effective, but there are other valuable recommendations. You should:
Yellow fever is typically spread to humans from bites by infected mosquitoes. People cannot spread yellow fever among themselves through casual contact, although the infection can be transmitted directly into the blood through contaminated needles.
A few different species of mosquitoes transmit the yellow fever virus; some breed in urban areas, others in jungles. Mosquitoes that breed in the jungle also transmit yelllow fever to monkeys, who, in addition to humans, are a host for the disease.
Yellow fever gets its name from two of its most obvious symptoms: fever and yellowing of the skin. The yellowing occurs because the disease causes liver damage, hepatitis. For some people, yellow fever has no initial symptoms, while for others, the first symptoms appear from three to six days after exposure to the virus from a mosquito bite. An infection with yellow fever typically has three phases. The first phase of symptoms can last for three to four days and then, for most people, disappears. The first phase is generally non-specific and cannot be distinguished from other viral infections. The initial symptoms of yellow fever are: The third-phase symptoms of yellow fever can include:
The next phase is remission, which lasts for 48 hours. Patients improve. The majority recover. Unfortunately, a third, more toxic phase of infection occurs for 15% to 25% of patients. Ultimately, a condition called viral hemorrhagic fever can develop, with internal bleeding (hemorrhaging), high fever, and damage to the liver, kidneys, and circulatory system. The World Health Organization estimates that up to 50% of people worldwide who reach this severe phase of infection die, while half recover.
Yellow fever is diagnosed by your symptoms, recent travel activity, and blood tests. Yellow fever symptoms can mimic symptoms of other tropical disease such as malaria and typhoid, so call your doctor if you have symptoms of yellow fever and have recently traveled to a high-risk country.
Because there is no cure for the viral infection itself, medical treatment of yellow fever focuses on easing symptoms such as fever, muscle pain, and dehydration. Because of the risk of internal bleeding, avoid aspirin and other nonsteroidal anti-inflammatory drugs if you suspect you have yellow fever. Hospitalization is often needed.
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Yellow fever, acute infectious disease, one of the great epidemic diseases of the tropical world, though it sometimes has occurred in temperate zones as well. The disease, caused by a flavivirus, infects humans, all species of monkeys, and certain other small mammals.
Yellow fever is an infectious disease caused by the yellow fever virus. Yellow fever is a vector-borne disease transmitted to humans by the bite of infected mosquitoes. Yellow fever is endemic in areas of Africa and South America.
Jan 15, 2019 · Yellow fever virus is an RNA virus that belongs to the genus Flavivirus. It is related to West Nile, St. Louis encephalitis, and Japanese encephalitis viruses. Yellow fever virus is transmitted to people primarily through the bite of infected Aedes or Haemagogus species mosquitoes.
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