How has the rapid scale up of malaria control in Africa impacted vector competence?

Introduction

The malaria parasite Plasmodium falciparum is responsible for more than 200 million cases and 400,000 deaths each year, with over 90% of cases occurring in Africa. The parasite is reliant upon Anopheline mosquitoes for transmission, and insecticide-treated bed nets targeting these mosquitoes represent the single most efficacious way to reduce case numbers and hence deaths.

Insecticide Resistance

However, due to the use of pyrethroid insecticides on all distributed insecticide-treated bed nets, insecticide resistance now threatens the impact of these interventions. Analogously, deaths from active malaria cases have been decreasing through the successful use of drug therapy; however, resistance to every class of front-line drug has now been described.

Knowledge Gaps

Incredibly, we simply do not know the impact of current vector control tools on parasite development nor the impact of drug resistance on development within the mosquito vector, despite fine-scale characterization in the erythrocytic stages. With the stalling of progress in malaria elimination and the addition of new chemistries to insecticide-treated bed nets, it is time that we invested in understanding precisely how our current vector control tools affect the parasite in order to avoid catastrophic failure of malaria control.

Proposed Research

To this end, I propose to:

1. Determine the impact of insecticide use on parasite development in the contexts of species replacement, insecticide resistance, and insecticide exposure.
2. Elucidate the changes due to parasite drug resistance on mosquito-stage development.
3. Ascertain genetic interplay between mosquito immunity and response to insecticides to identify new targets that negatively affect insecticide resistance and parasite development.

Expected Outcomes

The results generated from this multidisciplinary proposal will redefine our understanding of factors determining vector competence under contemporary transmission settings and will identify alternative options for intervention.