Vector control
Ae. aegypti proliferates in many purposely-filled household containers such as domestic water storage and those used for decorative plants, as well as rain-filled habitats – including used tyres, discarded containers, blocked gutters and buildings under construction.
Typically, these mosquitoes do not fly far. The majority remain within 100 metres of where they emerged, feeding almost entirely on humans mainly during daylight hours both indoors and outdoors.
Control of Ae. aegypti is mainly achieved by eliminating container habitats that favour the vetors lay or deposit their eggs and which permit the development of the aquatic stages.
The habitats are eliminated by frequently emptying and cleaning them these containers and by interrupting the aquatic stages of development through the use of insecticides either by biological control agents, killing adult mosquitoes using insecticides, or by combinations of these methods.
Historically, efforts to control dengue vectors in the WHO Region of the Americas resulted in the elimination of Ae. aegypti populations from much of the neotropics by the 1970s. However, re-introductions followed, leading to the re-establishment of vector populations. Today, the main aim is to reduce the densities of vector populations as much as possible and to maintain them at low levels. Where feasible, efforts should attempt at reducing the longevity of the adult female mosquito by insecticidal methods in order to lessen the risk of virus transmission.
In selecting the most appropriate vector control method, or combination of methods, consideration should be given to:
- local ecology and behaviour of the target species;
- resources available for implementation;
- cultural context in which control interventions are carried out;
- feasibility of applying control interventions in a timely manner, and
- the adequacy of coverage.
Methods of vector control include the elimination or management of larval habitats, larviciding with insecticides, the use of biological agents and the application of adulticides.