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Insecticide susceptibility status in individual species of the Anopheles gambiae complex (Diptera: Culicidae) in an area of The Gambia where pyrethroid impregnated bednets are used extensively for malaria control

Published online by Cambridge University Press:  10 July 2009

J. Hemingway*
Affiliation:
Department of Pure and Applied Biology, University of Wales Cardiff, UK
S.W. Lindsay
Affiliation:
Medical Research Council Laboratories, Banjul, The Gambia
G.J. Small
Affiliation:
Department of Pure and Applied Biology, University of Wales Cardiff, UK
M. Jawara
Affiliation:
Medical Research Council Laboratories, Banjul, The Gambia
F.H. Collins
Affiliation:
Department of Health and Human Services, Centres for Disease Control, Atlanta, Georgia, USA
*
Correspondenc: Department of Pure and Applied Biology, University of Wales Cardiff, PO Box 915, Cardiff CF1 3TL, UK.

Abstract

Pyrethroid-impregnated bednets are being used nationwide in The Gambia. The future success of this malaria control programme depends partly on the vectors remaining susceptible to those insecticides used for treating the nets. The present study was carried out on the south bank of the river Gambia, during the first large scale trial of nets in this country. Thus this area represents a sentinel site for detecting insecticide resistance in local vectors. This study gives an example of how a system of early detection for resistance problems can be set up in a relatively complex situation where multiple vectors and non-vectors are present. Samples of the Anopheles gambiae complex were caught indoors using light traps in twelve villages used in the bednet study. In all villages A. gambiae sensu stricto Giles was the predominant member of the complex as determined using the rDNA-PCR diagnostic assay. Limited bioassays with DDT and permethrin, and biochemical assays for a range of insecticide resistance mechanisms suggest that the A. gambiae complex remains completely susceptible to all major classes of commonly used insecticides including pyrethroids. Biochemical assays suggest that a low frequency of DDT resistance may occur in A. melas Theobald. This is based on elevated glutathione S-transferase levels coupled with increased levels of DDT metabolism and does not involve cross-resistance to pyrethroids. Therefore we do not envisage a decline in the efficacy of treated nets against malaria vectors in the study area in the immediate future, although monitoring should be continued whilst wide-scale use of impregnated bednets is operational.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1995

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References

Alonso, P.L., Lindsay, S.W., Armstrong, J.R.M., Conteh, M., Hill, A.G., David, P.H., Fegan, G., de Francisco, A., Hall, A.J., Shenton, F.C., Cham, K. & Greenwood, B.M. (1991) The effect of insecticide treated bednets on mortality of Gambian children. Lancet 337, 14991502.CrossRefGoogle Scholar
Davidson, G. (1956) Insecticide resistance in Anopheles gambiae Giles a case of simple Mendelian inheritance. Nature 178, 863.Google Scholar
Farnham, A.W.& Sawicki, R.M. (1976) Development of resistance to pyrethroids in insects resistant to other insecticides. Pesticide Science 7, 278282.CrossRefGoogle Scholar
ffrench-Constant, R.H. & Bonning, B.C. (1989) Rapid microtitre plate test distinguishes insecticide resistant acetylcholinesterase genotypes in the mosquitoes Anopheles albimanus, An. nigerrimus and Culex pipiens. Medical & Veterinary Entomology 3, 916.Google ScholarPubMed
Greenwood, B.M. & Baker, J.R. (1993) A malaria control trial using insecticide-treated bednets and targeted chemoprophylaxis in a rural area of The Gambia, West Africa. Transactions of the Royal Society of Tropical Medicine and Hygiene 87, Supplement pp. 60.Google Scholar
Haridi, A.M. (1972) Inheritance of DDT resistance in species A and B of the Anopheles gambiae complex. Bulletin of the World Health Organization 47, 619626.Google Scholar
Hemingway, J., Malcolm, C.A., Kissoon, K.E., Boddington, R.G., Curtis, C.F. & Hill, N. (1985) The biochemistry of insecticide resistance in Anopheles sacharovi: comparative studies with a range of insecticide susceptible and resistant Anopheles and Culex species. Pesticide Biochemistry and Physiology 24, 6876.Google Scholar
Hemingway, J., Boddington, R.G., Harris, J. & Dunbar, S.J. (1986) Mechanisms of insecticide resistance in Aedes aegypti (L.) (Diptera: Culicidae) from Puerto Rico. Bulletin of Entomological Research 79, 123130.Google Scholar
Herath, P.R.J., Jayawardena, K.G.I., Hemingway, J. & Harris, J. (1988) DDT resistance in Anopheles culicifacies Giles and A. subpictus Grassi (Diptera: Culicidae) from Sri Lanka: a field study on the mechanisms and changes in gene frequency after cessation of DDT spraying. Bulletin of Entomological Research 78, 717723.CrossRefGoogle Scholar
Lindsay, S.W., Alonso, P.L., Armstrong Schellenberg, J.R.M., Hemingway, J., Adimah, J., Shenton, F.C., Jawara, M. & Greenwood, B.M. (1993a) A malaria control trial using insecticide-impregnated bed nets and targeted chemoprophylaxis in a rural area of The Gambia, West Africa. 7. Impact of permethrin impregnated bed nets on malaria vectors. Transactions of the Royal Society of Tropical Medicine and Hygiene 87, 4552.CrossRefGoogle Scholar
Lindsay, S.W., Alonso, P.L., Armstrong Schellenberg, J.R.M., Hemingway, J., Thomas, P.J., Shenton, F.C. & Greenwood, B.M. (1993b) A malaria control trial using insecticide- impregnated bed nets and targeted chemoprophylaxis in a rural area of The Gambia, West Africa. 3. Entomological characteristics of the study area. Transations of the Royal Society of Tropical Medicine and Hygiene 87, 1924.CrossRefGoogle Scholar
Lines, J.D. & Nassor, N.S. (1991) DDT resistance in Anopheles gambiae declines with mosquito age. Medical and Veterinary Entomology 5, 261265.CrossRefGoogle ScholarPubMed
Paskewitz, S.M. & Collins, F.H. (1989) Use of the polymerase chain reaction to identify mosquito species of the Anopheles gambiae complex. Medical and Veterinary Entomology 4, 367373.Google Scholar
Peiris, H.T.R. & Hemingway, J. (1990) Mechanisms of insecticide resistance in a temephos selected Culex quinquefasciatus (Diptera: Culicidae) strain from Sri Lanka. Bulletin of Entomological Research 80. 453457.CrossRefGoogle Scholar
Prapanthadara, L., Hemingway, J. & Ketterman, A.J. (1995) DDT-resistance in Anopheles gambiae Giles from Zanzibar Tanzania, based on increased DDT-dehydrochlorinase activity of glutathione S-transferases. Bulletin of Entomological Research 85, 267274.Google Scholar
Prassitisuk, C. & Busvine, J.R. (1977) DDT-resistant mosquito strains with cross-resistance to pyrethroids. Pesticide Science 8.527533.CrossRefGoogle Scholar
Rongsriyam, Y. & Busvine, J.R. (1975) Cross-resistance in DDT-resistant strains of various mosquitoes (Diptera: Culicidae). Bulletin of Entomological Research 65, 459471.Google Scholar
Sawicki, R.M. (1975) Some aspects of the genetics and biochemistry of resistance of houseflies to insecticides. Report of the World Health Organization, WHO/VBC/EC. 75.10.Google Scholar
Snow, R.W., Lindsay, S.W., Hayes, R.J. & Greenwood, B.M. (1988) Permethrin-treated bednets (mosquito nets) prevent malaria in Gambian children. Transactions of the Royal Society of Tropical Medicine and Hygiene 82, 838842.Google Scholar
Vulule, J.M., Beach, R.F., Atieli, F.K., Roberts, J.M., Mount, D.L. & Mwangi, R.W. (1994) Reduced susceptibility of Anopheles-gambiae to permethrin associated with the use of permethrin-impregnated bednets and curtains in Kenya. Medical and Veterinary Entomology 8, 7175.CrossRefGoogle ScholarPubMed