Yellow Fever

What is yellow fever?

Yellow fever is a viral disease transmitted between humans by the bite of an infective mosquito.

It is characterized by:

• Acute onset of fever
• Hepatitis (inflammation of the liver)
• Abuminuria (protein in the urine)

followed by a brief remission, and then:

• Recurrence of fever
• Hepatitis
• Albuminuria
• In some instances:
  • Renal (kidney) failure
  • Shock
  • Generalized hemorrhages (bleeding)

Who gets yellow fever?

Yellow fever occurs only in the tropics.

In South America sporadic infections occur almost exclusively in forestry and agricultural workers from occupational exposure in or near forests.

In Africa, the virus is transmitted in three regions:

1. In the moist savanna zones of West and Central Africa during the rainy season
2. In urban locations and villages
3. In jungle regions (not as often)

How is yellow fever spread?

Yellow fever is transmitted between humans by the bite of an infective mosquito.

How soon after exposure do symptoms appear?

Symptoms occur within 3-6 days after infection with the virus.

How is yellow fever diagnosed?

Yellow fever is diagnosed by isolating the yellow fever virus from tissues, blood, or other body fluid, or, for those persons who have not been vaccinated, by measuring specific antibodies in the blood.

What is the treatment for yellow fever?

There is no specific treatment for yellow fever, other than supportive care.

How can yellow fever be prevented?

There are two actions travelers can take to avoid yellow fever:

1. General precautions to avoid mosquito bites should be followed by everyone.
2. Most adults and children over nine months of age can receive the yellow fever vaccine.
   • The vaccine is not recommended for pregnant women during the first trimester.

General precautions to avoid mosquito bites include the use of insect repellent, protective clothing, and mosquito netting.

Yellow fever vaccine is a live virus vaccine that has been used for several decades. A single dose confers immunity lasting 10 years or more.

The vaccine is available at the Southern Nevada Health District Immunizations Clinic. If a person is at continued risk of yellow fever infection, a booster dose is needed every 10 years.

Some countries require travelers to have received yellow fever vaccine within the last 10 years as a condition for entry. These conditions change periodically.

Consult your doctor, the Health District or a travel clinic to learn of the current requirements of the area(s) to which you will be traveling.

Where can I get more information?

Contact your physician or the Southern Nevada Health District, Office of Epidemiology at (702) 759-1300.

The Division of Quarantine, National Center for Infectious Diseases, Centers for Disease Control and Prevention has information on yellow fever and other diseases of concern to travelers at http://www.cdc.gov/travel/index.htm.

This information is based on the Centers for Disease Control and Prevention’s Information on Yellow Fever sheet (last updated 4/2/97).