Yellow fever is a serious disease caused by the yellow fever virus, which is found in certain parts of Africa and South America. The virus is spread through the bite of an infected mosquito. Some people who get infected will have no symptoms; others may have flu-like symptoms or severe symptoms. Most people recover without any long-term effects.
Yellow fever is a serious disease caused by the yellow fever virus. It is found in certain parts of Africa and South America.
Yellow fever is spread through the bite of an infected mosquito. Mosquitoes become infected when they feed on infected humans or monkeys. Infected mosquitoes can then spread the virus to humans when they bite.
Yellow fever is not contagious, meaning it is not passed directly from humans to other humans. It is not spread through casual contact, such as touching or kissing a person with the virus.
Transmission of the virus occurs in two main ways: urban (mosquito bites an infected human) and sylvatic (mosquito bites an infected monkey).
(Click Transmission of the Yellow Fever Virus for more information on how a person might get infected with the virus.)
When a person becomes infected with the yellow fever virus, the virus begins to multiply inside the body. After three to six days, the symptoms of yellow fever can occur. This period between becoming infected and the start of symptoms is called the incubation period.
Yellow fever symptoms vary among individuals. Some will have no symptoms, others may develop flu-like symptoms, and some may develop very serious symptoms, including death.
(Click Yellow Fever Symptoms for more information on the symptoms and signs of this disease.)