Indoor Residual Spraying Many malaria vectors are considered
"endophilic"; that is, the mosquito vectors rest inside houses
after taking a blood meal. These mosquitoes are particularly
susceptible to control through indoor residual spraying (IRS).
What Is Indoor Residual Spraying? As its name implies, IRS
involves coating the walls and other surfaces of a house with a
residual insecticide. For several months, the insecticide will
kill mosquitoes and other insects that come in contact with
these surfaces. IRS does not directly prevent people from being
bitten by mosquitoes. Rather, it usually kills mosquitoes after
they have fed if they come to rest on the sprayed surface. IRS
thus prevents transmission of infection to other persons. To be
effective, IRS must be applied to a very high proportion of
households in an area (usually >80%). History of IRS IRS with
DDT was the primary malaria control method used during the
Global Malaria Eradication Campaign (1955-1969). The campaign
did not achieve its stated objec