yellow fever

Yellow fever is an infectious disease caused by a virus carried by mosquitoes of the genus Aëdes and occurring in tropical South America and 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 to 6 days later.


Symptoms of yellow fever include fever, headache, backache, prostration, and vomiting of sudden onset. Protein loss in the urine, kidney failure, and liver disorder with jaundice are also frequent. Hemorrhage from mucous membranes, especially in the gastrointestinal tract is also common.


Yellow fever has three stages:


  • Early stage: Headache, muscle aches, fever, loss of appetite, vomiting, and jaundice are common. After about 3 to 4 days, often symptoms go away briefly (remission).

  • Period of remission: After 3 to 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.

  • Period of intoxication: Multi-organ dysfunction occurs. This includes liver and kidney failure, bleeding disorders/hemorrhage, and brain dysfunction including delirium, seizures, coma, shock, and death.


    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)


    If 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 to 14 days before traveling if you should be vaccinated.



    In 1900, physician Jesse Lazear, at age 34, was bitten by a mosquito carrying yellow-fever while conducting experiments in Quemados, Cuba, to investigate the transmission of te disease. His death, two weeks later, proved that the mosquito was the carrier of yellow fever.