Yellow fever is a viral disease that a person can get from being bitten by
an infected mosquito.
More to Know
Yellow fever is caused by a virus carried by mosquitoes. Someone bitten by an infected
mosquito might develop symptoms 3-6 days later, but most people don't get sick or
have only mild symptoms. If someone does develop symptoms, these can include fever,
vomiting, and jaundice
(a condition that turns the skin yellow — hence the disease's name). Symptoms
often go away after 3-4 days. At that point, most people with yellow fever recover
In about 15% of cases, the person may become sick again within a day or two. This
stage of the disease can lead to seizures, organ failure, and internal bleeding. While
rare, a case of yellow fever in this stage is a serious life-threatening condition
that requires immediate medical attention.
Keep in Mind
Yellow fever usually is found only in tropical areas of Africa and South America.
Very few cases happen in the United States. There is no cure for yellow fever, but
there is an effective vaccination that travelers can get before going to areas where
the disease is common.
All A to Z dictionary entries are regularly reviewed by KidsHealth medical