Black-fly and the Environment

Abstract

Black-fly (Simulium spp.) occurs practically through out the world. It poses biting problems wherever it is found. In Africa, black-fly carries a human disease called Onchocerciasis or river blindness. The World Health Organization has decided on a £50 million project, spreading over 20 years, to control this disease. They propose to apply, very extensively and protractedly, larvicides which are non-selective, reasonably persistent, and only mildly toxic to Man and other higher animals but fatally toxic to Simulium larvae (the target) and some other forms of aquatic life (non-target). This will result in the reduction of the already small quantities of fish available to the people. It will also put at risk the lives of the animals that constitute the major source of the scanty protein supply of the local populace, and hence conceivably jeopardize their own lives.The decision to go ahead with the project was based on the grounds that chemical control of Simulium breeding is the only sure method of dealing with Onchocerciasis, and that the areas of West Africa to be affected are among the least developed. But foreseeable consequences of the project alone are considered serious enough to justify its reconsideration, while quite likely consequences are powerful enough in themselves to make such as review seem necessary.Until such a time as the world is able to devise a universally acceptable method of controlling black-fly, the current method of treatment preventing Onchocerciasis from causing blindness should be extended to all areas where the disease is present.