The MalariaWorld Journal

This GCE project set out to develop a novel way of controlling malaria-transmitting mosquitoes by deploying live, insect-eating plants around houses and in mosquito breeding sites. Field surveys were undertaken to collect and identify carnivorous plants. Aldrovanda vesiculosa and Utricularia reflexa were collected from swamps in various locations in Uganda and brought to the laboratory where they were kept in distilled water into which larvae of Anopeheles gambiae were introduced and the impact of the plants studied.

To supplement current malaria prevention methods, and accelerate efforts towards elimination, this GCE project explores the use of outdoor mosquito control devices that mimic real humans, to attract and kill disease-transmitting vectors on a sustained basis. The idea (as envisioned in a GCE Phase I grant (2009) and Phase II grant (2011)) is to lure female Anopheles mosquitoes onto these outdoor ‘pseudo-hosts’, when positioned at optimally selected sites within or around human settlements, and then either trap these mosquitoes, contaminate them with substances that reduce their survival and ability to transmit disease or kill them instantly or within a few days after contact with the devices, thereby reducing exposure to mosquito bites and mosquito-borne pathogens.

This GCE project explored an RNAi strategy to control mosquitoes and prevent spread of mosquito-borne diseases. The strategy involved delivery of double-stranded RNA(dsRNA) elements to mosquito larvae using unicellular, transgenic algae as vectors. Significantly, microorganisms, including microalgae, are the primary source of nutrition for mosquito larvae in water bodies that serve as the breeding grounds for mosquitoes. This strategy of delivering RNA elements to suppress essential target genes in mosquito larvae has many potential advantages over existing technologies.

In this GCE project it was aimed to put a gene encoding a pathogen protein into a mosquito chromosome, causing it to express the protein in its saliva and inject it into animals orhumans during the blood-feeding process. It was anticipated that the host would develop antibodies to the recombinant protein. If transgenic mosquitoes whose saliva contained a vaccine protein against a disease are released in an area where the disease is prevalent, people that are bitten daily by these mosquitoes would develop antibodies to the vaccine protein, and ultimately the entire community would be ‘vaccinated’ against the disease. In this situation, mosquitoes would play the role of vaccine deliverers.