The Aedes aegypti mosquito is black with white bands on its legs and body

Mosquito larvae - or 'wrigglers' - must live in water for 7-14 days

Aedes aegypti pupae - the final aquatic stage before emerging as adult mosquitoes

Only female Aedes aegypti transmit dengue because only females bite (or blood-feed)

Aedes aegypti occur in more than 100 countries worldwide

Aedes aegypti

The mosquito Aedes aegypti is responsible for transmitting dengue between people. In some communities other mosquitoes may also contribute to transmission, but their contribution is very minor.

Aedes aegypti originates from Africa but is now distributed globally in tropical and subtropical regions. Global redistribution was assisted by mass human migrations, first to the New World associated with the slave trade between the 15th to 19th centuries, and then to Asia as a result of trade during the 18th and 19th centuries. Worldwide redistribution occurred after World War II following troop movement.

Added to this global distribution of the mosquitoes, rapid human population growth and increased urbanisation has led to substandard housing, inadequate water supply and waste management systems, and consequently an abundance of mosquito breeding sites. Storage of drinking water and other urban water, containers including plant-pot bases, guttering, tarpaulins, tyres and discarded containers can all collect rainwater and provide habitat for Aedes aegypti larvae.

Importantly, mosquitoes do not naturally carry the dengue virus. Mosquitoes must acquire it from a dengue-infected person before they can transmit it to another person. Only female mosquitoes bite, requiring the blood for egg production, and therefore only female mosquitoes transmit the dengue virus.