Indoor residual spraying
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Indoor residual spraying or IRS is the process of spraying the inside of dwellings with an insecticide to kill mosquitoes that spread malaria. A dilute solution of insecticide is sprayed on the inside walls of certain types of dwellings—those with walls made from porous materials such as mud or wood but not plaster as in city dwellings. Mosquitoes are killed by the spray, preventing the transmission of the disease. Several pesticides have historically been used for IRS, the most well-known being DDT.
[edit] World Health Organization recommendations
According to the World Health Organization:[1]
[N]ational governments should:
- 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.
- 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.
- 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 monitoring and evaluation.
The WHO states that "insecticide susceptibility and vector behaviour; safety for humans and the environment; and efficacy and cost-effectiveness" are factors that must be considered when selecting an insecticide for IRS.[1]
[edit] WHO approved insecticides for IRS
| Insecticide | Class | Recommended dosage of active ingredient (g/m2)[2] | Duration of effective action (months) | Estimated cost per house pewr 6 months (US$)[3] | WHO toxicity rating[4] |
|---|---|---|---|---|---|
| DDT | Organochlorine | 1–2 | >6 | 1.60 | II |
| Fenitrothion | Organophosphate | 2 | 3–6 | 14.80 | II |
| Malathion | Organophosphate | 2 | 2–3 | 8.20 | III |
| Pirimiphos-methyl | Organophosphate | 1–2 | 2–3 | III | |
| Propoxur | Carbamate | 1–2 | 3–6 | 18.80 | II |
| Bendiocarb | Carbamate | 0.1–0.4 | 2–6 | 13.80 | II |
| Alpha-cypermethrin | Pyrethroid | 0.02–0.03 | 4–6 | II | |
| Cyfluthrin | Pyrethroid | 0.02–0.05 | 3–6 | II | |
| Deltamethrin | Pyrethroid | 0.02–0.025 | 3–6 | 1.60 | II |
| Etofenprox | Pyrethroid | 0.1–0.3 | 3–6 | U | |
| Lambda-cyhalothrin | Pyrethroid | 0.02–0.03 | 3–6 | 8.60 | III |
| Bifenthrin | Pyrethroid | 0.025–0.05 | 3–6 | II |
[edit] References
- ^ a b Indoor Residual Spraying: Use of Indoor Residual Spraying for Scaling Up Global Malaria Control and Elimination. World Health Organization, 2006.
- ^ Sadasivaiah, Shobha; Tozan, Yesim & Breman, Joel G. (2007), “Dichlorodiphenyltrichloroethane (DDT) for Indoor Residual Spraying in Africa: How Can It Be Used for Malaria Control?”, Am. J. Trop. Med. Hyg. 77 (Suppl 6): 249–263, <http://www.ajtmh.org/cgi/content/full/77/6_Suppl/249>
- ^ "Excluding operational costs and freight and other external costs"
- ^ Ia = Extremely Hazardous; Ib = Highly Hazardous; II = Moderately Hazardous; III = Slightly Hazardous; U = Unlikely To Be Hazardous. Source: World Health Organization, The WHO Recommended Classification of Pesticides by Hazard, 2005.
