A survey of sleeping sickness in Northern Nigeria from the earliest times to the present day

The purpose of this paper has been to define the basic sleeping sickness situation in Northern Nigeria and to interpret later events in terms of that situation as far as possible. A primordial endemic zone of classical Gambian sleeping sickness has long existed along the valleys of the Niger and Benue rivers and the adjacent parts of their tributaries. A more diffuse primordial zone exists along certain rivers draining into Lake Chad. Here the disease is more acute and periods of quiescence are interrupted by disruptive epidemics at intervals of about 25 years. The development of man-made intensifications of the Niger-Benue focus and of extensions from this focus have been described, and a general account has been given of the work of the Sleeping Sickness Service of Northern Nigeria in reducing the consequences of these events. The present situation is described, its potential dangers have been pointed out, and suggestions made which may help in deciding future lines of sleeping sickness and tsetse control work. The need for fundamental research and professional staff at this critical juncture is emphasized.