Yellow Fever

What is yellow fever?

Yellow fever is a virus transmitted through the bite of an infected Aedes aegypti mosquito. It is most commonly found in tropical and subtropical areas in South America and Africa. It is very uncommon for U.S. citizens to get yellow fever while traveling internationally.

What are the symptoms of yellow fever?

Symptoms usually begin to show 3-6 days after infection. Symptoms may include:

Onset of fever
Chills
Severe headache
Body aches and back pains
Nausea and vomiting
Fatigue and weakness
Jaundice
Bleeding, especially in the gastrointestinal tract
Eventual shock and failure of many organs

Most people will improve after the initial flu-like symptoms. About 15% of people with yellow fever will experience the more severe symptoms, including bleeding and organ failure. About 20%-50% of people with severe yellow fever will die from complications.

How is yellow fever diagnosed?

A blood test can determine if the virus or antibodies protecting against the virus are present in the body.

How is yellow fever treated?

There is no specific treatment for yellow fever, but patients with yellow fever should be hospitalized to help treat their symptoms. Rest, plenty of fluids, and pain medications can help relieve some symptoms caused by yellow fever.

How can travelers prevent getting yellow fever?

Yellow fever can be prevented by:

Getting the vaccine. People aged 9 months or older should get the vaccine if they live or travel to areas where yellow fever is common.
Use insect repellent. Use an EPA-registered insect repellent any time you go outdoors.
Wear protective clothing. Wearing long sleeves, pants, and socks can prevent the risk for getting mosquito bites. Sometimes mosquitoes can bite through thin clothing, so spray with insect repellent as well.
Sleep with mosquito nets. Many mosquitoes bite at night, so sleep with protective mosquito nets.
Protect yourself during peak times. Aedes aegypti mosquitos, which cause yellow fever, feed during daytime hours. Protect yourself with insect repellent and clothing when the mosquitoes are at their peak feeding time.