What is Yellow Fever?
Yellow fever is a viral tropical disease that is spread to humans by infected mosquitoes. The disease is caused by a virus. Most yellow fever infections are mild. However, the disease can cause severe, life-threatening illness. Yellow fever is found only in parts of Africa and South America. Yellow fever has caused large epidemics in Africa and Northern and Southern America.

Yellow fever is characterized by fever, jaundice, and hemorrhage.

Yellow fever is caused by a small virus that is spread by the bite of mosquitoes. This disease is common in South America and in sub-Saharan Africa.

Anyone can get yellow fever, but the elderly have a higher risk of severe infection. If a person is bitten by an infected mosquito, symptoms usually develop 3 - 6 days later.

Yellow fever has three stages:
1. Early stage: Headache, muscle and joint aches, fever, flushing, loss of appetite, vomiting, and jaundice are common. After approximately 3 - 4 days, often symptoms go away briefly (remission).
2. Period of remission: After 3 - 4 days, fever and other symptoms go away. Most people will recover at this stage, but others may move onto the third, most dangerous stage (intoxication stage) within 24 hours.
3. Period of intoxication: Multi-organ dysfunction occurs. This may include heart, liver, and kidney failure, bleeding disorders, hemorrhage, and brain dysfunction including delirium, seizures, coma, shock, and death.

Kinds of Yellow Fever
There are two kinds of Yellow Fever: jungle (Sylvatic) yellow fever and urban yellow fever. Jungle Yellow fever usually occurs in monkeys. It is spread from infected monkeys to humans by the bite of an infected female mosquito. Jungle Yellow fever is rare and usually occurs in individuals who work in tropical rain forests.

Urban Yellow Fever is a disease that usually occurs in humans. It is spread by the bite of an infected female mosquito that have infected other people. They type of mosquito that usually carries the yellow fever is called Aedes aegypti. Urban yellow fever is the cause of most yellow fever outbreaks.

Female and not male mosquito
Female mosquitoes transmit the virus because they take blood from the bitten victim. Male mosquitoes do not take blood from the victim. After the mosquito ingests the virus, it takes about a week to ten days or so for that mosquito to become infective.

Can Yellow Fever be prevented?
Yes. Yellow fever is preventable by immunization. Travelers to countries with yellow fever should get the yellow fever vaccine.

Symptoms of Yellow Fever
There are many symptoms of yellow fever. The symptoms vary from person to person and one person may not experience all of the symptoms.
Some of the most common symptoms of yellow fever are:
high fever
chills
headache
muscle aches
vomiting
backache

Symptoms of yellow fever usually appear between 3 and 6 days after being infected by a mosquito.

Yellow fever must be monitored by a doctor. After a brief recovery period, the infection may lead to shock, bleeding, and kidney and liver failure.

 Exams and Tests
A person with advanced yellow fever may show signs of liver failure, renal failure, and shock.
If you have symptoms of yellow fever, tell your doctor if you have traveled to areas where the disease is known to thrive. Blood tests can confirm the diagnosis.

How is Yellow Fever diagnosed?
Yellow fever is diagnosed by a blood test.

Who is at risk for Yellow Fever?
People are at risk when they travel to an area where there is yellow fever in humans or monkeys and there are mosquitoes to spread the virus.

Complications of Yellow Fever
Severe yellow fever infections can be fatal.

Can Yellow Fever be Treated?
Rest is the usual treatment. However, if you are infected with yellow fever, follow the advice of your doctor.

Select Language English Russian French German Italian Japanese Korean Portuguese Spanish Greek Dutch Hindi