Yellow fever is a viral infection spread by a particular species of mosquito. It’s most common in areas of Africa and South America, affecting travelers to and residents of those areas.
In mild cases, yellow fever causes fever, headache, nausea and vomiting. But yellow fever can become more serious, causing heart, liver and kidney problems along with bleeding (hemorrhaging). Up to 50 percent of people with the more severe form of yellow fever die of the disease.
There’s no specific treatment for yellow fever. But getting a yellow fever vaccine before traveling to an area in which the virus is known to exist can protect you from the disease.
Symptoms
During the first three to six days after you’ve contracted yellow fever — the incubation period — you won’t experience any signs or symptoms. After this, the virus enters an acute phase and then, in some cases, a toxic phase that can be life-threatening.
Acute phase
Once the yellow fever virus enters the acute phase, you may experience signs and symptoms including:
Fever
Headache
Muscle aches, particularly in your back and knees
Nausea, vomiting or both
Loss of appetite
Dizziness
Red eyes, face or tongue
These signs and symptoms usually improve and are gone within several days.
Toxic phase
Although signs and symptoms may disappear for a day or two following the acute phase, some people with acute yellow fever then enter a toxic phase. During the toxic phase, acute signs and symptoms return and more-severe and life-threatening ones also appear. These can include:
Yellowing of your skin and the whites of your eyes (jaundice)
Abdominal pain and vomiting, sometimes of blood
Decreased urination
Bleeding from your nose, mouth and eyes
Heart dysfunction (arrhythmia)
Liver and kidney failure
Brain dysfunction, including delirium, seizures and coma
The toxic phase of yellow fever can be fatal.
Causes
Yellow fever is caused by a virus that is spread by the Aedes aegypti mosquito. These mosquitoes thrive in and near human habitations where they breed in even the cleanest water.
Complication
Yellow fever results in death for 20 to 50 percent of those who develop severe disease. Death usually occurs within two weeks from the start of infection. Complications during the toxic phase of a yellow fever infection include kidney and liver failure, jaundice, delirium and coma.
People who survive the infection recover gradually over a period of several weeks to months, usually without significant organ damage. During this time a person may experience fatigue and jaundice. Other complications include secondary bacterial infections, such as pneumonia or blood infections.
Treatment
No antiviral medications have proved helpful in treating yellow fever. As a result, treatment consists primarily of supportive care in a hospital. This includes providing fluids and oxygen, maintaining adequate blood pressure, replacing blood loss, providing dialysis for kidney failure, and treating any other infections that develop. Some people receive transfusions of plasma to replace blood proteins that improve clotting.
If you have yellow fever, you may also be kept away from mosquitoes, to avoid transmitting the disease to others.
Prevention
Vaccine
A safe and highly effective vaccine prevents yellow fever.
Mosquito protection
In addition to getting the vaccine, you can help protect yourself against yellow fever by protecting yourself against mosquitoes
