Yellow Fever is a serious and sometimes fatal viral disease that is spread by mosquitoes in tropical parts of Africa and South America. The mosquito which transmits yellow fever (Aedes Egypti) bites during daylight hours unlike the malaria mosquito which operates in hours between dusk and dawn. It occurs in both jungle and urban environments and is particularly common in the rainy season.

Yellow fever can be fatal in those individuals that have not received immunisation. General symptoms may include fever, nausea and pain, with some patients entering a more serious stage of the illness involving jaundice, haemorrhagic fever and deterioration of kidney function. Some patients that develop this form of the disease die within 7-10 days after the onset.

Yellow fever occurs in tropical parts of South America and sub-Saharan and West Africa.

Nearly all affected countries require proof of yellow fever vaccination in the form of an International Certificate of Vaccination before they allow a traveller to enter. Failure to provide a valid certificate can lead to a traveller being denied entry.

There is no treatment for yellow fever. The yellow fever vaccine (stamaril) is a live vaccine given as a single dose and the immunity from this lasts for 10 years with the vaccine nearly 100% effective at preventing infection with yellow fever.