The control of Simulium damnosum at Abuja, Northern Nigeria, 1955-60.

This paper gives a comprehensive account of the first six years of operation of an onchocerciasis control pilot project in an area of over 3000 km(2) in the Abuja Emirate, Northern Nigeria. Control was attempted by the use of DDT against the larvae of the vector, Simulium damnosum. For the first two years technical DDT in diesel oil was applied. Later, this insecticide was used in miscible liquid form; this formulation gave as good results as the technical DDT and was easier to handle and apply.The authors conclude that, by the methods and in the conditions described, 90% control (although not eradication) of S. damnosum can be achieved by the addition of DDT to river water and that the best results are obtained by application in the early wet season, from May to July.Although the cost of the operations was relatively high, it is thought that the concentration of DDT actually used could be lowered with no loss in efficacy and that this, together with some reduction in the number of treatment-points, might reduce costs to a level that could be met by a local administration.