Challenges and approaches for mosquito targeted malaria control

Abstract

Malaria is one of today's most serious diseases with an enormous socioeconomic impact. While anti-malarial drugs have existed for some time and vaccines development may be underway, the most successful malaria eradication programs have thus far relied on attacking the mosquito vector that spreads the disease causing agent Plasmodium. Here we will review past, current and future perspectives of malaria vector control strategies and how these approaches have taken a promising turn thanks recent advances in functional genomics and molecular biology.

Fig. (1). Targets for malaria control strategies

Panel A, the mosquito nervous system serves as a target for the control of mosquito adults and larvae, through the action of insecticides and larvicides. Panel B, a set of strategies targets the sensory system of mosquitoes through the use of host attractant-baited traps and behavior modification through the use of repellents. Lower Panel B, mosquito-human interactions: anticoagulants, vasodilators, and immune suppressor compounds are synthesized and used by mosquitoes to successfully feed on blood. Panel C, Plasmodium lifecycle in the mosquito and targets for control strategies: 1) Plasmodium gametocytes enter the mosquito midgut with the ingestion of an infectious blood meal; 2) gametocytes mature into female (macrogamete) and male (microgamete) gametes; 3) fertilization of both gametes occurs in the mosquito midgut, giving rise to a zygote; 4) the zygote further matures into an ookinete that is able to penetrate the midgut epithelium; 5) once the Plasmodium ookinete reaches the area between the epithelium and the basement membrane, it matures into an oocyst; 6) aproximately10 days after blood feeding, the mature oocyst bursts, releasing thousands of sporozoites that migrate and invade the salivary glands. The sporozoites are then inoculated during feeding, along with the mosquito saliva, into the skin of the next human host. Numbers in red represent three major mosquito compartments in which mosquito-Plasmodium interactions occur: I = midgut lumen, II = midgut epithelium, III = hemocoele and salivary glands.