PROSPECTS FOR GENETIC MANIPULATION OF INSECT VECTORS AS A STRATEGY FOR THE CONTROL OF VECTOR-BORNE DISEASE

Abstract:
Insect vector control has proved to be an effective method for reducing the transmission of disease-causing organisms to human populations in many tropical countries. A variety of methods have been employed to suppress vector populations, including the application of biological control agents and the elimination of breeding sites, with a continuing and heavy reliance on the use of chemical insecticides. However, the development of insecticide resistance by vector insects, the cost of developing and registering new insecticidal compounds, and the increase in legislation to combat the detrimental effects of insecticidal residues on the environment, have emphasised the need to assess a variety of alternatives to vector control. What is required is a completely novel approach either to suppress vector populations, or to alter their ability to transmit disease-causing organisms in such a way as to have a profound and long-lasting effect on disease transmission. Genetic manipulation of insect vectors may provide just such an approach. The major requirements for being able to manipulate the genomes of insects will be reviewed, together with the progress which has been made to create transgenic vector insects. The potential of this methodology will then be explored, emphasising how its most immediate use will be as an analytical tool. Finally, the feasibility of creating refractory vector strains by genetic manipulation and releasing them into the environment will be assessed in relation to its future use as a disease control strategy.