Genetically Modified Mosquitoes for Malaria Control

Despite a century of research and attempts to control one of the deadliest foes of mankind, the malaria situation remains a major public health problem. Obviously biological explanations (the resistance of parasites and mosquitoes against available drugs and insecticides respectively) are often given, but they remain partial and incomplete. Indeed, the deterioration of socio-economic conditions due to the policies imposed on many developing countries by international financial institutions, such as the structural adjustment programmes and the mechanism of debt, plays an important role in the malaria situation and its evolution.

In the last decade, molecular biology has been a source of great hope for creating genetically-modified mosquitoes able to resist the malaria parasite. If technical progress permits confidence in the creation of such non-vectors, many questions remain open concerning the putative success of their deployment and the resultant reduction of malaria transmission. Indeed the understanding of the coevolutionary processes underlying malaria/mosquito interactions is crucially lacking despite its enormous importance. Moreover, when discussing transgenic mosquitoes, one critical point is the spread of the allele conferring resistance in mosquito populations ensuring the replacement of a or several populations of vectors able to transmit malaria by (theoretically) unable one(s). However, invading a whole population of mosquitoes with a transgene (composed with an allele conferring malaria-resistance and a driving system) is unlikely to be an easy task, it will at least depend on the population structure and on the quality of the driver. Alongside this, it appears that the spread of refractoriness itself is necessary but not sufficient as interactions between the allele of interest, the parasite and the environment may affect refractoriness and thus limit the expected success in terms of malaria control. Indeed the aim of a release of transgenic mosqui