Yellow fever

Answer 1

A tropical viral disease affecting the liver and kidneys, causing fever and jaundice and often fatal. It is transmitted by mosquitoes. Caused problem in the construction of the Panama Canal.

Answer 2

Definition

Yellow fever is a viral infection transmitted by mosquitoes.

Causes, incidence, and risk factors

Yellow fever is caused by a small virus that is spread by the bite of mosquitoes. This disease is common in South America and in sub-Saharan Africa.

Anyone can get yellow fever, but the elderly have a higher risk of severe infection. If a person is bitten by an infected mosquito, symptoms usually develop 3 - 6 days later.

Yellow fever has three stages:

1. Early stage: Headache, muscle and joint aches, fever, flushing, loss of appetite, vomiting, and jaundice are common. After approximately 3 - 4 days, often symptoms go away briefly (remission).
2. Period of remission: After 3 - 4 days, fever and other symptoms go away. Most people will recover at this stage, but others may move onto the third, most dangerous stage (intoxication stage) within 24 hours.
3. Period of intoxication: Multi-organ dysfunction occurs. This may include heart, liver, and kidney failure, bleeding disorders, hemorrhage, and brain dysfunction including delirium, seizures, coma, shock, and death.

Symptoms

• Arrhythmias, heart dysfunction
• Bleeding (may progress to hemorrhage)
• Coma
• Decreased urination
• Delirium
• Fever
• Headache
• Jaundice
• Muscle aches (myalgia)
• Red eyes, face, tongue
• Seizures
• Vomiting
• Vomiting blood

Signs and tests

A person with advanced yellow fever may show signs of liver failure, renal failure, and shock.

If you have symptoms of yellow fever, tell your doctor if you have traveled to areas where the disease is known to thrive. Blood tests can confirm the diagnosis.

Treatment

There is no specific treatment for yellow fever. Treatment for symptoms can include:

• Blood products for severe bleeding
• Dialysis for kidney failure
• Fluids through a vein (intravenous fluids)

Expectations (prognosis)

Yellow fever varies in severity. Severe infections with internal bleeding and fever (hemorrhagic fever) are deadly in up to half of cases.

Complications

• Coma
• Death
• Disseminated intravascular coagulation (DIC)
• Kidney failure
• Liver failure
• Parotitis
• Secondary bacterial infections
• Shock

Calling your health care provider

Get medical attention at least 10 - 14 days before traveling to an endemic area for yellow fever to find out whether you should be vaccinated against the disease.

Tell your health care provider right away if you or your child develop fever, headache, muscle aches, vomiting, or jaundice, especially if you have traveled to an area where yellow fever is known to occur.

Prevention

If you will be traveling to an area where yellow fever is common:

• Sleep in screened housing
• Use mosquito repellents
• Wear clothing that fully covers your body

There is an effective vaccine against yellow fever. Ask your doctor at least 10 - 14 days before traveling if you should be vaccinated against yellow fever.

References

Bell M. Viral hemorrhagic fevers. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 404.

Answer 3

Definition

Yellow fever is a viral infection spread by mosquitoes.

Causes, incidence, and risk factors

Yellow fever is caused by a virus carried by mosquitoes. You can catch this disease if you are bitten by a mosquito infected with this virus.

This disease is common in South America and in sub-Saharan Africa.

Anyone can get yellow fever, but the elderly have a higher risk of severe infection.

If a person is bitten by an infected mosquito, symptoms usually develop 3 - 6 days later.

Symptoms

Yellow fever has three stages:

• Stage 1 (infection): Headache, muscle and joint aches, fever, flushing, loss of appetite, vomiting, and jaundice are common. Symptoms often go away briefly after about 3-4 days.
• Stage 2 (remission): Fever and other symptoms go away. Most people will recover at this stage, but others may get worse within 24 hours.
• Stage 3 (intoxication): Problems with many organs occur. This may include heart, liver, and kidney failure, bleeding disorders, seizures, coma, and delirium.

Symptoms may include:

• Irregular heart beats(arrhythmias)
• Bleeding (may progress to hemorrhage)
• Coma
• Decreased urination
• Delirium
• Fever
• Headache
• Yellow skin and eyes (jaundice)
• Muscle aches
• Red eyes, face, tongue
• Seizures
• Vomiting, possibly vomiting blood

Signs and tests

The health care provider will examine the person. This may show liver and kidney failure and shock.

It is important to tell your doctor if you have traveled to areas where the disease is known to thrive. Blood tests can confirm the diagnosis.

Treatment

There is no specific treatment for yellow fever. Treatment for symptoms can include:

• Blood products for severe bleeding
• Dialysis for kidney failure
• Fluids through a vein (intravenous fluids)

Expectations (prognosis)

Yellow fever can cause severe problems, including internal bleeding. Death is possible.

Complications

• Coma
• Death
• Disseminated intravascular coagulation (DIC)
• Kidney failure
• Liver failure
• Parotitis
• Secondary bacterial infections
• Shock

Calling your health care provider

Get medical attention at least 10 - 14 days before traveling to an endemic area for yellow fever to find out whether you should be vaccinated against the disease.

Tell your health care provider right away if you or your child develop fever, headache, muscle aches, vomiting, or jaundice, especially if you have traveled to an area where yellow fever is known to occur.

Prevention

If you will be traveling to an area where yellow fever is common:

• Sleep in screened housing
• Use mosquito repellents
• Wear clothing that fully covers your body

There is an effective vaccine against yellow fever. Ask your doctor at least 10 - 14 days before traveling if you should be vaccinated against yellow fever.

References

Bausch DG. Viral hemorrhagic fevers.In: Goldman L, Schafer AI, eds.Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 389.

Reviewed By

Review Date: 12/06/2011

David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School, Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.