Facts about Yellow Fever

According to WHO, 2005 figures, an estimated 200 000 people are infected, and 30 000 people die from yellow fever each year. The virus is endemic in tropical regions of Africa and the Americas. Check Maps Here.

The protective effect (immunity) occurs within one week in 95% of people vaccinated.

You should have a yellow fever vaccination at least 10 days before your travel.


Yellow fever is a viral haemorrhagic fever – (Arbovirus of the flavivirus genus) transmitted to people by infected Aedes and Haemogogus mosquitoes.

Sylvatic (or jungle) yellow fever: In Tropical Rain Forests, Yellow Fever occurs in Monkeys that are infected by wild mosquitoes. These infected monkeys pass the virus to other mosquitoes that feed on them. The infected mosquitoes bite human beings and other living animals entering the forest, resulting in new cases of yellow fever.

Intermediate yellow fever: In humid or semi-humid parts of Africa, small-scale epidemics occur. Semi-domestic mosquitoes (that breed in the wild and around households) infect both monkeys and humans. Increased contact between people and infected mosquitoes leads to transmission. Many separate villages in an area can suffer cases simultaneously. This is the most common type of outbreak in Africa. An outbreak can become a more severe epidemic if the infection is carried into an area populated with both domestic mosquitoes and unvaccinated people.

Urban yellow fever: Large epidemics occur when infected people introduce the virus into densely populated areas with a high number of non-immune people and Aedes mosquitoes. Infected mosquitoes transmit the virus from person to person.

Image from Infection Landscapes

Symptoms of Yellow Fever:


  • Hadache
  • High temperature
  • Nausea and vomiting
  • Jaundice – yellowing of the skin and whites of the eyes
  • Bleeding



  • 20-50% of those with severe illness will die of the disease.
  • The “yellow” in the name is explained by the jaundice, it means yellow discoloration of eyes and skin.

For More Information please follow the links from WHO

Global Alert and Response (GAR)

All about Yellow fever