Hostname: page-component-7c8c6479df-xxrs7 Total loading time: 0 Render date: 2024-03-27T21:17:06.667Z Has data issue: false hasContentIssue false

Comparison of permethrin treatments for bednets in The Gambia

Published online by Cambridge University Press:  10 July 2009

R.J. Pleass*
Affiliation:
London School of Hygiene and Tropical Medicine, London, UK
J.R.M. Armstrong
Affiliation:
London School of Hygiene and Tropical Medicine, London, UK
C.F. Curtis
Affiliation:
London School of Hygiene and Tropical Medicine, London, UK
M. Jawara
Affiliation:
Medical Research Council Laboratories, Fajara, The Gambia
S.W. Lindsay
Affiliation:
Medical Research Council Laboratories, Fajara, The Gambia
*
Mr R.J. Pleass, The Wellcome Research Centre for Parasitic Infections, Imperial College of Science Technology & Medicine, The West Wing, Prince Consort Road, London SW7 2BB, UK.

Abstract

An experimental hut trial of bednets was undertaken in The Gambia to compare six different permethrin treatments, including a wash-resistant formulation, and to test the effect of thorough hand washing of the nets. The wash-resistant formulation on nylon and cotton nets deterred Anopheles gambiae Giles (sensu lato) from house entry. All treated bednets killed a significantly higher number of A. gambiae (sensu lato) than untreated nets. The ability to kill mosquitoes was not diminished with the wash-resistant and Wellcome formulations after washing unlike the normal ICI formulation, this result being consistent with the permethrin residues found by gas liquid chromatographic (GLC) analyses to persist on the nets after washing. The mortality on treated cotton nets was significantly less than on treated nylon nets. Of the unwashed nets only the cotton net was significantly repellent. Both washed and unwashed treated nets significantly reduced the proportion of human bloodfed mosquitoes that survived and were potentially able to transmit malaria. Although the wash-resistant formulation might prove more efficient at killing mosquitoes with time, as compared to the other treatments, in The Gambia, where women wash their nets frequently, we suggest that the cheapest and most readily available formulation is used on nylon nets where possible.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

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 bed nets on mortality of Gambian children. Lancet 337, 14991502.Google Scholar
Burkot, T.R., Goodman, W.G.. & DeFoliart, G.R. (1981). Identification of mosquito bloodmeals by Enzyme Linked Immunoabsorbent assay. American Journal of Tropical Medicine and Hygiene 30, 13361341.Google Scholar
Charlwood, J.D.. & Dagaro, H. (1988). Collateral effects of bed nets impregnated with permethrin in controlling bed bugs (Cimicidae) in Papua New Guinea. Transactions of the Royal Society of Tropical Medicine and Hygiene 83, 261.Google Scholar
Cochran, W.G.. & Cox, G.M. (1957). Experimental Designs. 611pp. New York, Wiley.Google Scholar
Curtis, C.F., Lines, J.D., Carnevale, P., Robert, V., Boudin, C., Halna, J.M., Pazart, L., Gazin, P., Richard, A., Mouchet, J., Charlwood, J.D., Graves, P.M., Hossain, M.I., Kurihara, T., Ichimori, K., Li, Zuzi., Lu, Baolin., Majori, G., Sabatinelli, G., Coluzzi, M., Njunwa, K.J., Wilkes, T.J., Snow, R.. & Lindsay, S.W. (1989) Impregnated bednets and curtains against malaria mosquitoes. pp. 546 in Curtis, C.F. (Ed.) Appropriate technology for vector control. Boca Raton, C.R.C.Google Scholar
Darriet, F., Robert, V., Tho Vien, N.. & Carnevale, P. (1984) Evaluation of the efficacy of permethrin impregnated intact and perforated mosquito nets against vectors of malaria. World Health Organization mimeographed document, WHO/VBC/84.899.Google Scholar
Hossain, M.I., Curtis, C.F.. & Heekin, J.P. (1989). Assays of permethrin-impregnated fabrics and bioassays with mosquitoes. Bulletin of Entomological Research 79, 299308.Google Scholar
Lindsay, S.W., Adiamah, J.H., Miller, J.E.. & Armstrong, J.R.M. (1991c) Pyrethroid-treated bednet effects on mosquitoes of the Anopheles gambiae complex in The Gambia. Medical and Veterinary Entomology 5, 477483.Google Scholar
Lindsay, S.W., Hossain, M.I., Bennet, S.. & Curtis, C.F. (1991b) Preliminary studies of the insecticidal activity and wash fastness of 12 synthetic pyrethroid treatments impregnated into bednetting assayed against mosquitoes. Pesticide Science 32, 297341.Google Scholar
Lindsay, S.W., Snow, R.W., Armstrong, J.R.M.. & Greenwood, B.M. (1989) Permethrin impregnated bednets (mosquito nets) reduce nuisance arthropods in Gambian houses. Medical and Veterinary Entomology 3, 377383.Google Scholar
Lindsay, S.W., Wilkins, H.A., Zieler, H.A., Daly, R.J., Petrarca, V., Byass, P. (1991a). Ability of Anopheles gambiae mosquitoes to transmit malaria during the dry and wet seasons in an area of irrigated rice cultivation in The Gambia. Journal of Tropical Medicine and Hygiene 94, 313324.Google Scholar
Magesa, S.W., Wilkes, T.J.. Mnzava, A.E.P., Njunwa, K.J., Myamba, J., Kivuyo, M.D.P., Hill, N., Lines, J.D.. & Curtis, C.F. (1991) Trial of pyrethroid impregnated bednets in an area of Tanzania holoendemic for malaria. Part 2. Effects on the malaria vector population. Acta Tropica 49, 97108.Google Scholar
Miller, J.E. (1990) Laboratory and field studies of insecticide impregnated fibres for mosquito control. PhD Thesis, University of London.Google Scholar
Payne, C.D. (1986). The GLIM system Release 3.77 Manual. 183 pp. Oxford, Numerical Algorithms Group.Google Scholar
Rozendaal, J.A. (1989) Impregnated mosquito nets and curtains for self-protection and vector control. Tropical Diseases Bulletin (Supplement) 86, 141.Google Scholar
WHO (World Health Organization) (1989) The use of impregnated bednets and other materials for vector-borne disease control. WHO mimeographed document (WHO/VBC/89.981). 45 pp. Geneva, World Health Organization.Google Scholar
WHO (World Health Organization Press Release) (1991) 35 pp.Google Scholar