ABSTRACT

C. F. Curtis, J. D. Lines, P. Carnevale, V. Robert, C. Boudin, J.-M. Halna, L. Pazart, P. Gazin, A. Richard, J. Mouchet, J. D. Charlwood, P. M. Graves, M. I. Hossain, T. Kurihara, K. Ichimori, Li Zuzi, Lu Baolin, G. Majori, G. Sabatinelli, M. Coluzzi,

K. J. Njunwa, T. J. Wiikes, R. W. Snow, and S. W. Lindsay

I. Untreated and Treated Netting as Protection Against Mosquitoes 6

II. Laboratory Experiments on Pyrethroid-Impregnated Netting 8 A. Chemical and Physical Studies 8 B. Bio-Assays on Pyrethroid-Impregnated Netting 11 C. Behaviorial Studies in the Laboratory 16

III. Experimental Hut Studies 19

IV. Field Trials of Impregnated Nets for Malaria Control 23 A. Trials in The Gambia 23 B. Trial of Deltamethrin-Impregnated Bed Nets in Burkina Faso 25

1. Entomological Evaluation 27 2. Parasitological and Clinical Evaluation 27 3. Malaria Attacks 30

C. Trial of Permethrin-Impregnated Nets in Tanzania 30 D. Papua New Guinea 32 E. Sabah, Malaysia, and Solomon Islands 32 F. Field Trials and Use of Pyrethroid-Treated Mosquito Nets for

Malaria Control in China 33 1. Trials against An. anthropophagus and An. sinensis 33

a. Field Trials and Applications of Nets in Guangdong Province 33

b. Impregnation of Mosquito Nets in Jiangsu Province 34

c. Deltamethrin treatment of nets in Sichuan Province 36

2. Deltamethrin against An. dims in Hainan Province 36

V. Prospects for the Application of Pyrethroid-Impregnated Nets or Curtains to Large-Scale Malaria Control 38 A. Time People Spend Under Nets and Time of Mosquito Biting 38 B. Safety and Acceptability 41 C. Cost 42 D. Resistance 43

References 43

Malaria is by far the most important insect-borne disease. For example, in Ghana it is top of the list of causes of loss of days of healthy life, and no other insect-borne disease ranks in the top 25 on this list.1 The Anopheles vectors of malaria may be attacked in their aquatic larval stages (see Chapters 7 and 8) or as adults in houses where most of them come to bite people. The latter approach has the advantages that:

1. Houses are generally easier to find and treat than are the seasonally shifting puddles etc. where Anopheles typically breeds.