ENTOMOLOGICAL ASPECTS OF THE 1ST 5 YEARS OF THE ONCHOCERCIASIS CONTROL PROGRAM IN THE VOLTA RIVER BASIN

Abstract

The history and structure of the WHO Onchocerciasis Control Program in the Volta River Basin [West Africa] are described. An outline of the vector control operations is given, and the techniques and organization of the entomological evaluation network are described in detail. During the course of the evaluation and related studies undertaken between Nov. 1974 and Oct. 1978 almost 1.2 million Simulium damnosum females were taken in over 52,000 man days of catching, and 674,000 flies were dissected. An assessment based on this effort using annual biting rates and annual transmission potentials showed that the transmission of Onchocera volvulus was reduced to below a defined maximum permissible level over most of the central part of the Program area. The difficulties encountered in the remainder, and at certain problem sites were outlined. The benefits to be expected from extending the area further southwards and the possibilities of later reductions in control activity are discussed.