A key target set out in the global strategic plan of the Roll Back Malaria Partnership is “for 80% of people at risk from malaria to be protected by 2010, thanks to locally appropriate vector control such as insecticide-treated nets and indoor residual spraying” (WHO, 2005). In order to achieve this target the insecticides used to treat bed nets and other surfaces must be efficacious in reducing human blood feeding either by personally protecting the sleeper under the net or by community wide mass killing effect.

Pyrethroid treated nets are the main means of preventing malaria, particularly in Africa where the disease is a leading health problem. This technology is threatened by the development and rapid spread of pyrethroid resistance in the Anopheles gambiae and Anopheles funestus species complexes as reported in several parts of Africa.

The pyrethroid knockdown resistance gene (kdr) is known to be widespread in Anopheles gambiae sensu stricto in many areas of western Africa and has also been reported in parts of eastern Africa. Although kdr initially appeared to be no obstacle to malaria control in many areas (Henry et al., 2005), the recent emergence and spread of pyrethroid resistance and/or kdr in the M taxon of An. gambiae may severely limit the effectiveness of ITN and IRS (N’Guessan et al., 2007; Sharp et al., 2007). The situation is complicated by varied distribution of malaria vectors and the existence of multiple mechanisms of resistance including oxidase mechanisms.

There is an urgent need to look for alternative insecticides which meet criteria for vector control and show no cross-resistance to pyrethroids. Such insecticides have been developed by pesticide manufacturers for the agricultural sector where market size provides greater potential rewards and profitability than the public health sector.

Several of these insecticides have given encouraging results against vector mosquitoes and show potential for malaria control. The particular advantage of the Benin site is its situation in a zone of emerging pyrethroid resistance of operational significance. Any chemical product that aims to replace the pyrethroids needs to prove itself in this testing ground.