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  • New bed nets 'twice as effective' against mosquitoes

French scientists have developed a new type of anti-mosquito bed net that they claim is more effective against mosquitoes compared with existing nets, yet is safer for humans to use.

Jean-Marc Hougard  and Vincent Corbel from the Institut de Recherche pour le Développement (IRD) in Montpelier, France, tested bed nets coated with a mixture of two insecticides, bifenthrin and carbosulfan.

Tests in the laboratory showed that nets impregnated with just one insecticide killed around 40 per cent of mosquitoes. In contrast, the new nets killed twice as many —  80 per cent —  using just one-fiftieth the recommended dose of bifenthrin and half the recommended dose of carbosulfan.

The results of a field trial of the new nets, conducted in the Ivory Coast, showed that the combined insecticide was as effective at killing mosquitoes as bed nets impregnated with just one insecticide — but using one tenth of the equivalent dose.

"It consequently reduces the cost and toxicity of the treatment, thus ensuring the safety of users, especially of children," say the researchers.

The IRD research was prompted by the fact that species of mosquito such as Anopheles gambiae, the main malaria carrier in sub-Saharan Africa, are becoming increasingly resistant to certain insecticides. Around 3,000 children die from malaria daily in Africa, and bed nets can cut child deaths by 20 per cent.