Aedes mosquitoes

The yellow fever mosquito, Aedes aegypti, and the Asian tiger mosquito, Aedes albopictus, are the principle vectors of the viral diseases dengue, yellow fever and chikungunya.

Aedes aegypti originated from Africa but is now distributed around the world in most tropical and sub tropical countries. The spread is driven by global travel and trade and urbanisation. It is highly adapted to the urban environment, living in and around buildings, laying its eggs in containers such as air-conditioning trays, plant pots and discarded cans and biting during the day. Dengue fever is sometimes called an ‘urban disease’ due to the prevalence of the vector in towns and cities. Aedes albopictus originated in Asia but is now also globally spread – following the trade of used tyres. See map.

Aedes female mosquitoes spread disease by transferring the virus when they bite people to obtain the bloodmeal for the nutrition of their offspring. As there are no vaccines for dengue or chikungunya, people can only protect themselves by preventing themselves from being bitten – using repellents or physical barriers like clothing – or by killing the mosquitoes.

Aedes mosquito control today relies on mechanical breeding-site reduction, public education and chemical insecticides, including larvicides and adulticides as space sprays, fogs and indoor residual sprays. The insecticide-treated bednets (ITNs) that are used to protect people against the night-biting Anopheles mosquitoes are ineffective against the day-biting Aedes mosquitoes. Because of the huge diversity of breeding sites Aedes mosquitoes use, it is impossible for human vector-control professionals to identify and treat every breeding site and even intensive spray programs are not effective in reducing mosquito populations to levels below which dengue transmission occurs. The increase in insecticide resistance is making the problem worse. A new solution is needed.

Oxitec’s approach meets the challenge of finding the target mosquitoes by harnessing the natural instinct of the male mosquito to seek out females, and taking advantage of the fact that male mosquitoes don’t bite. The exploitation of this instinct makes sterile insect approaches successful at reducing low insect populations to effectively zero. We have developed Aedes aegypti and Aedes albopictus strains for both Asia and the Americas to help protect communities from dengue fever, chikungunya and yellow fever.