A new study has found that indoor spraying with the insecticide bendiocarb dramatically reduced malaria transmission in many parts of Benin, Africa.
The finding provides new evidence that insecticides remain a potent weapon for fighting malaria despite the rapid rise of resistance to an entire class of mosquito-killing compounds.
Scientists with Benin”s Entomologic Research Centre in Cotonou evaluated the effects of two applications of bendiocarb in homes throughout the West African country over an eight-month period in 2009.
They found that after “indoor residual spraying” or IRS, which involves applying insecticide on walls where mosquitoes are likely to land, none of the 350,000 household members living in the treated homes “received infected bites” from the malaria-carrying mosquito Anopheles gambiae.
Moreover, none of the mosquitoes collected from the treated homes tested positive for the Plasmodium falciparum—the world’s most deadly malaria parasite.
The absence of infected bites and parasites was seen as evidence that malaria transmission had fallen precipitously in an area where mosquitoes have developed resistance to permethrin and other members of a popular class of insecticides known as pyrethroids.
The study was published in the October edition of The American Journal of Tropical Medicine and Hygiene.