What is yellow fever?
Yellow fever (YF) is a serious illness caused by the YF virus. YF is usually passed on to humans by the bite of an infected mosquito. YF can vary from a flue-like illness that gets better on its own over several days to a severe illness with fever, jaundice (turning yellow), bleeding and organ failure.
There is no specific medicine to treat YF. Most people with the disease will need to be admitted to hospital and treated for their symptoms, some in intensive care. Many people who get YF will die from the disease.
Where does yellow fever occur?
YF occurs in some tropical parts of South America and sub Saharan Africa. Although most cases occur in the countryside, YF can also occur in cities. It is estimated that there are around 200,000 cases of YF in risk areas each year, although it is likely that many more cases occur but do not get reported. Most cases occur in Africa.
How can I prevent yellow fever?
There are two ways to prevent YF:
Travellers to YF areas should do both things.
Mosquitoes that transmit YF tend to bite during the daytime, particularly in the hours after dawn and before dusk. If visiting a YF risk area, you are advised to prevent mosquito bites day and night.
Ways of preventing bites are:
Permethrin should not be used directly on the skin. More detailed information about avoiding mosquito bites can be found on the NATHNAC’s TravelHealthPro website:
If you are having the YF vaccine for the first time, you should have it at least 10 days before you travel. For most travellers, the vaccine is expected to provide life-long protection. Rarely, travellers are advised to have a further dose; a health professional at a Yellow Fever Vaccination Centre (YFVC) can tell you if this applies to you. Call us on 0203 659 3149 or book an appointment using our booking form.