Genetic Control of Mosquitoes: population suppression strategies

Abstract

SUMMARYOver the last two decades, morbidity and mortality from malaria and dengue fever among other pathogens are an increasing Public Health problem. The increase in the geographic distribution of vectors is accompanied by the emergence of viruses and diseases in new areas. There are insufficient specific therapeutic drugs available and there are no reliable vaccines for malaria or dengue, although some progress has been achieved, there is still a long way between its development and actual field use. Most mosquito control measures have failed to achieve their goals, mostly because of the mosquito's great reproductive capacity and genomic flexibility. Chemical control is increasingly restricted due to potential human toxicity, mortality in no target organisms, insecticide resistance, and other environmental impacts. Other strategies for mosquito control are desperately needed. The Sterile Insect Technique (SIT) is a species-specific and environmentally benign method for insect population suppression, it is based on mass rearing, radiation mediated sterilization, and release of a large number of male insects. Releasing of Insects carrying a dominant lethal gene (RIDL) offers a solution to many of the drawbacks of traditional SIT that have limited its application in mosquitoes while maintaining its environmentally friendly and species-specific utility. The self-limiting nature of sterile mosquitoes tends to make the issues related to field use of these somewhat less challenging than for self-spreading systems characteristic of population replacement strategies. They also are closer to field use, so might be appropriate to consider first. The prospect of genetic control methods against mosquito vectored human diseases is rapidly becoming a reality, many decisions will need to be made on a national, regional and international level regarding the biosafety, social, cultural and ethical aspects of the use and deployment of these vector control methods.

Targeting male mosquito swarms to control malaria vector density

“…Consequently, this study constitutes an important paradigm shift from current and past malaria vector control strategies that have essentially focused on killing female mosquitoes. As of today, no serious study had been conducted based on the premise of reducing the mosquito population by targeting males [20]. The massive deployment of treated bednets and indoor residual spraying over the last decades has drastically changed the landscape of malaria [21].…”

Transmission-Blocking Antibodies against Mosquito C-Type Lectins for Dengue Prevention

“…A promising live-attenuated tetravalent dengue vaccine developed by Sanofi Pasteur has been shown to induce partial protection against infection with dengue virus serotypes and is being advanced in clinical trials [41]. Given the rapid increase in dengue spread and disease burden over the last decade, additional strategies are urgently needed to combat dengue dissemination [42], [43], [44], [45]. The survival of the dengue virus is restricted to its interaction between humans and Aedes mosquitoes.…”

Genetically modified insects as a public health tool: discussing the different bio-objectification within genetic strategies

“…Eradication is usually difficult to accomplish. In case it is not achieved, when releases are stopped, the non-GM mosquito population will increase again (7). …”

“…It requires releases of sufficient numbers of genetically engineered organisms to pass a threshold to ensure that GM individuals will replace the entire wild type population. In theory, once this threshold has been passed, the transgene is self-sustaining and releases would need to occur only once or a few times (7). Nonetheless, the strategies within this approach are still in development at laboratories and these relations with the environment are somewhat speculative (16).…”