WHO/CDS/NTD/WHOPES/GCDPP/2007.2 GLOBAL INSECTICIDE USE FOR VECTOR-BORNE DISEASE CONTROL M. Zaim & P. Jambulingam DEPARTMENT OF CONTROL OF NEGLECTED TROPICAL DISEASES (NTD) WHO PESTICIDE EVALUATION SCHEME (WHOPES) First edition, 2002 Second edition, 2004 Third edition, 2007 © World Health Organization 2007 All rights reserved. The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. Dotted lines on maps represent approximate border lines for which there may not yet be full agreement. The mention of specific companies or of certain manufacturers’ products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature that are not mentioned. 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CONTENTS Page Acknowledgements i Introduction 1 Collection of information 2 Data analysis and observations on reporting 3 All uses in vector control 6 Malaria vector control 22 Dengue vector control 38 Chagas disease vector control 48 Leishmaniasis vector control 52 Other vector-borne disease control 56 Selected insecticides – DDT 58 Selected insecticides – Insect growth regulators 60 Selected insecticides – Bacterial larvicides 62 Country examples 64 Annex 1. Data reporting form and instructions for completion 78 ACKNOWLEDGEMENTS The Department of Control of Neglected Tropical Diseases (NTD) of the World Health Organization (WHO) thanks the many individuals in Member States who assisted NTD in collecting and validating data on the use of insecticides to control vector-borne diseases. Special thanks are extended to the following staff in WHO regional offices for their valuable assistance in facilitating data collection: - Dr B. Ameneshewa, WHO Regional Office for Africa, Harare, Zimbabwe - Dr M. Ejov, WHO Regional Office for Europe, Copenhagen, Denmark - Dr C. Frederickson, Caribbean Epidemiology Centre, Pan American Health Organization, Port-of-Spain, Trinidad and Tobago - Dr L. Manga, WHO Regional Office for Africa, Brazzaville, Congo - Dr A. Mnzava, WHO Regional Office for the Eastern Mediterranean, Cairo, Egypt - Dr K. Palmer, WHO Regional Office for the Western Pacific, Manila, Philippines - Dr C. Prasittisuk, WHO Regional Office for South-East Asia, New Delhi, India - Dr G. Zamani, WHO Regional Office for the Eastern Mediterranean, Cairo, Egypt This publication was funded by the Global Collaboration for Development of Pesticides for Public Health. i WHO/CDS/NTD/WHOPES/GCDPP/2007.2 Page 1 INTRODUCTION Vector control constitutes an important element in the current global strategy for the control of major vector-borne diseases, and chemical control remains an important element in an integrated approach to vector control. In order to support the development of products to control vectors, facilitate the judicious use of insecticides and effectively manage insecticide resistance, there is a need to develop pesticide management systems based on regular monitoring and reporting of insecticide use in different disease control programmes. An attempt has been made to document the use of insecticides for vector control at the global level (WHO, 20021,2), which could form the basis for the following: development of guidelines on safe and effective use of insecticides; development of guidelines for management of insecticide resistance; agreements for international use of insecticides (e.g. DDT, re-registration of insecticides in certain countries and how that may affect their international use); investment for development of alternatives; review and formulation of policies for insecticide usage at different levels (national, regional and global levels). This document is a continuation of such effort and contains information on the global use of insecticides for control of vector-borne diseases for the reporting period 2003–2005. 1 Zaim M (2002). Global insecticide use for vector-borne disease control. Geneva, World Health Organization (WHO/CDS/WHOPES/GCDPP/2002.2). 2 Zaim M, Jambulingam P (2004). Global insecticide use for vector-borne disease control, 2nd ed. Geneva, World Health Organization (WHO/CDS/WHOPES/GCDPP/2004.9). WHO/CDS/NTD/WHOPES/GCDPP/2007.2 Page 2 COLLECTION OF The data on the use of insecticides in vector-borne disease control programmes were collected and validated, with the assistance of WHO regional offices, from the national INFORMATION disease control programmes, using a standard questionnaire (Annex 1). Only Member States having vector-borne diseases as their major public health problem were approached for such information. The WHO Pesticide Evaluation Scheme (WHOPES) invites national disease control programmes to report regularly on the use of insecticides for vector control, using the questionnaire provided in Annex 1. They are also invited to submit data on such use for the missing years, in order to obtain a clear understanding of insecticide use at national, regional and global levels. WHO/CDS/NTD/WHOPES/GCDPP/2007.2 Page 3 DATA ANALYSIS A total of 81 countries from the six WHO regions responded to the questionnaire as follows: African Region, (20); Region of the Americas, (25); Eastern Mediterranean AND Region (11); European Region (6); South-East Asia Region, (6); and Western Pacific OBSERVATIONS Region (13). ON REPORTING While many countries provided information for the entire three-year reporting period (2003–2005), others provided information for either two years or just one year. A few countries provided data on insecticide use pooled with those for more than one vector- borne disease. Such data were not included in the analysis of insecticide use for specific diseases but used only to estimate the total use of insecticides for vector control. While the data provided by most countries were on the use of the four major classes of insecticides (see below), some countries also reported on the use of bacterial larvicides and/or insect growth regulators. Such data are presented separately in this document. The number of countries reporting to WHOPES on insecticide use for vector control remains almost the same as in the previous survey. In addition, some countries updated their information by providing data for the missing years. Comparison of data from the current survey with previous surveys was done using the updated information. As in the previous survey, one of the reasons cited by countries for not providing complete data is that decentralized programmes have difficulty in collecting such information. This is a matter of major concern that could adversely affect the management of insecticides for vector control. It is therefore important that these countries take adequate steps to develop appropriate and effective monitoring and reporting systems for insecticide use in their vector-borne disease control programmes. WHO/CDS/NTD/WHOPES/GCDPP/2007.2 Page 4 DATA ANALYSIS The major vector-borne diseases reportedly controlled with insecticides were: AND - malaria, caused by protozoan Plasmodium parasites transmitted by Anopheles OBSERVATIONS mosquitoes; ON REPORTING - dengue, Japanese encephalitis, yellow fever and other arboviruses transmitted by certain mosquitoes; - leishmaniasis, caused by protozoan Leishmania parasites transmitted by phlebotomine sandflies; - Chagas disease, caused by protozoan Trypanosoma cruzi parasites transmitted by triatomine bugs. The insecticides used against these disease vectors were mostly of the following classes, as detailed in other WHO documents:1,2 - organochlorines, of which DDT is the main insecticide used in vector control; - organophosphates such as fenitrothion, malathion and temephos; - carbamates such as bendiocarb and propoxur; - pyrethroids such as alpha-cypermethrin, cyfluthrin, cypermethrin, deltamethrin, etofenprox, lambda-cyhalothrin and permethrin; - insect growth regulators such as diflubenzuron, methoprene and pyriproxyfen; - bacterial larvicides such as Bacillus thuringiensis israelensis. 1 Pesticides and their application for the control of vectors and pests of public health importance (2006). Geneva, World Health Organization (WHO/CDS/NTD/WHOPES/GCDPP/2006.1). 2 Najera JA, Zaim M (2002). Malaria vector control – Decision making criteria and procedures for judicious use of insecticides. Geneva, World Health Organization (WHO/CDS/WHOPES/2002.5 Rev.1). WHO/CDS/NTD/WHOPES/GCDPP/2007.2 Page 5 DATA ANALYSIS The most common formulations of synthetic insecticides employed for particular AND applications were: OBSERVATIONS larvicidal treatments with emulsifiable concentrate and granules; ON REPORTING residual treatment with wettable powder, suspension concentrate and capsule suspension; treatment of mosquito nets with aqueous formulations such as suspension concentrate,