Vector resistance to pesticides : fifteenth report of the WHO Expert Committee on Vector Biology and Control [meeting held in Geneva from 5 to 12 March 1991]

Abstract

Assesses the global status of vector resistance to pesticides and recommends a number of specific technical measures that can be used to prevent or delay the further spread of resistance. Addressed to specialists in entomology, the book concentrates on recent advances that have refined understanding of how resistance develops and improved the precision of biochemical tests for detecting resistance and monitoring the susceptibility status of vectors. The report stresses the need to regard effective pesticides as a limited resource that must be conserved through careful planning and management based on the best scientific knowledge. The first main section features 14 pages of tables listing the species of anopheline mosquito, other insects, arthropod vectors, and rodent reservoirs that have shown some evidence of resistance to particular groups of chemicals in one or more populations. The second section provides a region-by-region and disease-by-disease summary of the extent of resistance to pesticides and the significance of the associated public health problems. Of particular practical value is a section offering detailed advice on tests that can be used to monitor the susceptibility status of vectors and thus guide strategies for preventing the further spread of resistance. Information includes a discussion of problems that have arisen during the field use and testing of 15 standard or tentative test kits developed and distributed by WHO. The report also compares the strengths and weaknesses of available biochemical assays for metabolic mechanisms that can be used when the role of the metabolic enzyme responsible for resistance has already been determined. The final main section describes 10 specific measures which can be applied to delay or prevent an increase in resistance levels to the point where a pesticide must be abandoned. The report concludes with a list of diagnostic dosages, or concentrations, and exposure times for various species of vectors and samples of newly modified WHO forms for recording WHO susceptibility test results