Yellow Fever FAQs

What is yellow fever?

  • An acute illness caused by the yellow fever virus which is found in the tropics of South America and Africa; not endemic to the Caribbean.
  • Affects people of all ages.


How is yellow fever spread?

  • Through the bite of an infected Aedes aegypti mosquito.
  • Mosquitoes may acquire the virus for life by biting either infected monkeys or infected humans.
  • Not spread from person to person.


What are the signs and symptoms?

The incubation period is 3-6 days.

First phase (acute):

  • Symptoms may be mild and go unnoticed, or severe, affecting many organ systems.
  • Symptomatic illness begins with fever, chills, headache, backache, general muscle pain, upset stomach, and vomiting.
  • Most patients improve and their symptoms disappear after 3 to 4 days.


Second phase (toxic):

Approximately, 15% of patients enter a second, more toxic phase within 24 hours of the initial remission.

  • If the disease progresses, weakness, jaundice, bleeding of the gums, hematemesis (vomiting of blood) and blood and protein in the urine may occur.
  • Bleeding occurs because of problems with clotting of blood. This is why yellow fever is referred to as a “hemorrhagic fever.”
  • Illness usually lasts two weeks, after which the patient either recovers or dies.
  • Persons who recover from yellow fever have lifelong immunity.


How is yellow fever diagnosed?

  • Diagnosis of yellow fever is difficult because its signs and symptoms are similar to those of other diseases, such as hepatitis, malaria, dengue, and typhoid fever. Any person who develops jaundice within 2 weeks of a fever, and has recently returned from travel in a yellow fever endemic area, or has been in contact with a return traveler, should be tested for yellow fever.
  • Blood tests can detect yellow fever antibodies produced in response to the infection.


What are the complications?

  • Liver and renal failure
  • Death


How is yellow fever treated?

  • There is no specific treatment for yellow fever.
  • Dehydration and fever can be corrected with oral rehydration solution and acetaminophen (e.g. paracetamol, tylenol). Any superimposed bacterial infection should be treated with an appropriate antibiotic.

Population at risk

At risk are 44 endemic countries in Africa and Latin America, with a combined population of over 900 million. In Africa, an estimated 508 million people live in 31 countries at risk. The remaining population at risk is in 13 countries in Latin America, with Bolivia, Brazil, Colombia, Ecuador and Peru at greatest risk.

Small numbers of imported cases occur in countries free of yellow fever.


How is yellow fever prevented?

  1. Immunization with yellow fever vaccine
    • The yellow fever vaccine is safe and affordable, and a single dose provides life-long immunity against the disease.
    • Given to Jamaicans traveling to high risk or endemic countries. The vaccines can be obtained through designated clinics in each region. These clinics provide the International Certificate of Vaccination required for travel to yellow-fever endemic countries.
    • When it is given
      • To travelers requiring an International Certificate of Vaccination for entry into an endemic or high-risk country.
      • It should be given at least 10 days prior to travel.
      • Persons 12 months of age and older may receive it.
      • Should NOT be given to children under 6 months of age.
  2. Control of Aedus aegypti mosquitoes
    • Mosquito control includes eliminating sites where mosquitoes can breed, and killing adult mosquitoes and larvae by using insecticides in areas with high mosquito density.
    • Community involvement through activities such as cleaning household drains and covering water containers where mosquitoes can breed is a very important and effective way to control mosquitoes.
  3. Vigilant surveillance is critical for prompt recognition and rapid control of outbreaks.
    • Yellow Fever is a Class I notifiable disease. Suspected cases should be reported to the parish health department within 24 hours, so that a case investigation and disease prevention and control measures may be put in place.


Yellow Fever Advisory and FAQ

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Yellow Fever Country Listing

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