Definition

Yellow fever is a disease carried by female mosquitoes. The species of mosquito that carry yellow fever are native to sub-Saharan Africa and South America, but can also be found in other areas. Although it may be rare in developed countries, yellow fever is endemic in impoverished areas where people cannot afford to get vaccinated.

There is no specific treatment for yellow fever, but vaccination can prevent it.

Causes

Yellow fever is caused by specific viruses transmitted by bites from infected mosquitoes.

Mosquito Bite

Mosquito bite
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Risk Factors

Factors that may increase your chances of getting yellow fever include:

  • Living, working, or traveling areas with yellow fever
  • Failure to take proper precautions, such as vaccination or using mosquito protection

Symptoms

Yellow fever symptoms appear within a week after a person is bitten by an infected mosquito. Typically, acute phase symptoms will persist for 3 to 4 days, and then disappear. A small percentage of people progress into the toxic phase. The toxic phase symptoms begin within 24 hours of the end of the acute phase. Recovery from yellow fever provides lifetime immunity from the disease.

Acute phase symptoms may include:

  • Fever
  • Headache
  • Muscle pain
  • Backache
  • Chills
  • Loss of appetite
  • Nausea and/or vomiting

Toxic phase symptoms may include:

  • High fever
  • Abdominal pain
  • Bleeding from the gums, nose, eyes, and/or stomach
  • Vomit that appears black due to blood content
  • Low blood pressure
  • Liver failure, which may lead to jaundice
  • Kidney failure
  • Confusion
  • Seizure
  • Coma

Diagnosis

Your doctor will ask you about your symptoms and medical and travel history. A physical exam will be done. Blood tests will be needed for diagnosis. Antibodies or the virus may be detected in the blood.

Treatment

Currently, medications or treatments specifically for yellow fever are not available. However, there are treatments that that can be given at a hospital to ease some symptoms of yellow fever.

Hydration

It is important to keep the body hydrated. Fluids containing electrolytes may be given orally, or may be injected through a vein to prevent dehydration.

Fever Reduction Methods

Cool water or anti-fever medications may be given to reduce fever.

Kidney Dialysis

In toxic phases, dialysis may be needed to help the kidneys filter waste.

Dialysis Mechanism

Dialysis pump
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Blood Transfusion

In toxic phase cases, a transfusion may be needed to replace blood cells and clotting agents lost through bleeding.

Antibiotics for Secondary Infections

Fighting yellow fever may cause the immune system to become temporarily weak. A weak immune system cannot guard against bacterial infections as it normally would, so infections occur more easily. Antibiotics may be given to fight bacterial infections if they occur. Antibiotics cannot be given to treat yellow fever because yellow fever is a virus, and viruses do not respond to antibiotics.

Prevention

Vaccination is the best way to prevent yellow fever. The yellow fever vaccine is recommended for people aged 9 months to 59 years who are traveling to or living in areas where the disease is present. Your doctor will help decide if the vaccine is right for you.

Other ways to reduce your chances of getting yellow fever include:

  • Staying in air-conditioned or well-screened areas.
  • Wearing long-sleeved clothing and long pants.
  • Using bed netting while sleeping.
  • Removing or destroying mosquito-breeding areas. Mosquitoes lay their eggs in standing pools of water, such as the inside of old tires, flower pots, and small puddles.
  • Using insect repellents containing DEET on exposed skin.
  • Using Permethrin or DEET on clothes and bed nets for extra protection.