Sterile Insect Technique

Female tsetse flies copulate only once in their lifetime. If this is with a sterile male, they cannot reproduce. The mass release of sterile male tsetse flies to control the insect population raises ethical problems. The sterile males are, indeed, not refractory to trypanosomes and their release thus temporarily increases the number of potential vectors. This technique was nevertheless used, for example in Zanzibar from 1994 to 1998. After a preliminary reduction of the tsetse fly population (Glossina austeni) with traps and screens, several million insects were produced over several years in the Tsetse Trypanosomiasis Research Institute in Tanga, Tanzania. Approximately 70,000 sterile male flies were released weekly. This led to the complete disappearance of the natural vector population. The intention was especially to control the animal disease nagana. Since Zanzibar lies tens of kilometres off the continental African coast, future reinfestation is unlikely.

Category: Medicine Notes