Oxitec and Dengue Fever

March 14, 2012

How can Oxitec control the spread of dengue fever?

Dengue fever, which at a conservative estimate infects 50 million people a year, is spread by the Aedes aegypti mosquito. It is a growing global problem with reported cases of the disease growing 30 fold in the last 50 years. Currently, mosquito populations are controlled by chemical pesticides which harm many other insects in addition to mosquitoes and have not stopped the spread of the disease.

Oxitec has developed an innovative solution, employing advances in genetics and molecular biology to create a novel solution for mosquito control. Oxitec ‘s solution harnesses the natural instincts of male mosquitoes to find females in the wild. After an Oxitec ‘sterile’ male has successfully mated with a wild female any offspring will not survive to adulthood. Releases of Oxitec mosquitoes over a sustained period of time can safely reduce the mosquito population and therefore the incidence of dengue fever.

For more information about dengue fever, the symptoms, how it is spread and current control methods, please visit our dengue information centre.

Problems with conventional SIT

Although SIT has proven effective technique to control some agriculturally important insect pests, it does have limitations. One major problem is that irradiating insects can damage their health. If the released males are less healthy than the wild males, they won’t compete well for females, and so aren’t very effective at reducing the population. This has proven a particular problem for mosquitoes as well as for many agricultural pests, such as Olive Fly. Oxitec’s technology improves the SIT technique by avoiding the use of harmful irradiation which may also cause unpredictable mutations in any surviving progeny.

Oxitec’s genetically modified insects don’t require radiation to be made sterile, so the males are fitter – in effect, more ‘attractive’ to females – than irradiated insects. This enables a much more cost-effective and successful release programme.

Further Reading:

The WHO records of dengue transmission

http://www.who.int/csr/disease/dengue/impact/en/

Control methods for dengue

Lux, P. M., T. Vanni, et al. (2011). “Dengue vector control strategies in an urban setting: an economic modelling assessment.” Lancet 377: 1673-1680.

Alphey, L. and M. H. Andreasen (2002). “Dominant lethality and insect population control.” Molecular and Biochemical Parasiology 121: 173-178.

Simmons, G. S., A. R. McKemey, et al. (2011). “Field performance of a genetically engineered strain of pink bollworm.” PLoS One 6(9): e24110.

Wilke, A. B. B., D. D. Nimmo, et al. (2009). “Mini-review: Genetic enhancements to the sterile insect technique to control mosquito populations ” Asian-Pacific Journal of Molecular Biology and Biotechnology 17(3): 65-74.