Yellow fever

Introduction

Yellow fever is a serious viral disease that is usually transmitted by a type of mosquito known as the Aedes aegypti mosquito.

Yellow fever mainly occurs in sub-Saharan Africa (countries to the south of the Sahara desert), South America and in parts of the Caribbean. There have not been any recent cases of yellow fever in north America, Europe or Asia.

Yellow fever can be fatal. About 5% of people who get yellow fever die from the condition.

Typical symptoms of yellow fever include:

  • headache,
  • high temperature (fever),
  • nausea and vomiting,
  • jaundice, and
  • bleeding (haemorrhage).

Types of yellow fever

There are two types of yellow fever:

Jungle yellow fever

Jungle yellow fever is spread by jungle mosquitoes and mainly affects non-human hosts, such as monkeys. Humans who spend time in a jungle habitat where the mosquito and infected monkeys live can get jungle yellow fever and can be responsible for causing outbreaks of urban yellow fever.

Urban yellow fever

Humans can get urban yellow fever if they are bitten by an Aedes aegypti mosquito that has previously bitten a monkey or human who has the yellow fever infection. The risk of an urban yellow fever outbreak occurring is highest in areas that are close to jungles where the mosquitoes and infected monkeys live.

Cases of both jungle and urban yellow fever most frequently occur in Africa (particularly west Africa). Urban yellow fever is rare in the Americas.

Yellow fever vaccination

The yellow fever vaccination is recommended for:

  • anyone travelling to or living in an area or country where yellow fever is a problem, and
  • anyone travelling to a country that requires an International Certificate of Vaccination against yellow fever for entry.

See Facts, above, for a list of countries where there is a risk of yellow fever. See Prevention for more details about the yellow fever vaccination and the International Certificate of Vaccination.

Last updated: 28 December 2011

Continue to next section: Facts about yellow fever