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.

When to see a doctor

Make an appointment to see your doctor four to six weeks before traveling to an area in which yellow fever is known to occur. If you don't have that much time to prepare, call your doctor anyway. Your doctor will help you determine whether you need vaccinations and can provide general guidance on protecting your health while abroad.

Seek emergency medical care if you've recently traveled to a region where yellow fever is known to occur and you develop severe signs or symptoms of the disease. If you develop mild symptoms, call your doctor.

Aug. 27, 2011

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