Indoor residual spraying

Indoor residual spraying is the process of spraying the inside of dwellings with a pesticide to kill mosquitoes that spread malaria. In the last 30 years, the practice has been controversial. Some authorities called it useless or disparaged its use as counterproductive or expensive, compared to bed nets, prophylactic tablets or simply treating the disease after infection occurs. Others said that when properly applied it can save lives and reduce malaria mortality from an epidemic to minor risk.

A solution of pesticide is sprayed by a specially-equipped, trained worker, on the inside walls of certain types of dwellings. The walls must be porous, such as mud or wood - not plaster as in city dwellings. One application works for 6 months or 1 year. The mosquitoes are either repelled or killed by the pesticide.

According to the World Health Organization's position paper on IRS:

"WHO recommends that national governments should:

monitoring and evaluation."
 * 1) Introduce and/or scale up coverage of targeted IRS as a primary malaria control intervention in countries where available data indicates that it can be effective towards achieving malaria targets.
 * 2) Take all necessary steps to ensure effective implementation of IRS interventions, including selecting the appropriate insecticide, spraying where and when necessary and sustaining a high level of coverage, and to prevent unauthorized or un-recommended use of public health insecticides.
 * 3) Strengthen the managerial capacity of national malaria control programmes and improve human, technical and financial resources for the timely delivery and high coverage of effective interventions including IRS, with adequate

The WHO recommeds the following insecticides for IRS :

Finally, in choosing an insectide for IRS, the WHO states the following factors must be considered:
 * 1) insecticide susceptibility and vector behaviour;
 * 2) safety for humans and the environment;
 * 3) efficacy and cost-effectiveness.