Insecticide-treated bedding materials (sheets and blankets) could be protective against vectors of malaria and leishmaniasis - especially in complex emergencies, epidemics and natural disasters where people are more likely to sleep in exposed situations. Comparison of cotton top-sheets impregnated with different pyrethroids (permethrin 500 mg/m2, deltamethrin 25 mg/m2 or alphacypermethrin 25 mg/m2) for effectiveness against mosquitoes (Diptera: Culicidae) was undertaken in a refugee camp in Pakistan. Predominant species encountered were Anopheles stephensi Liston, An. pulcherrimus Theobald, An. nigerrimus Giles, Culex quinquefasciatus Say, Cx. tritaeniorhynchus Giles and other culicine mosquitoes. All three pyrethroid treatments performed significantly better than the untreated sheets in deterrence and killing of mosquitoes. No significant differences were found between the three insecticides tested in terms of entomological effect. Washing of the treated sheets greatly reduced their effectiveness. In a user acceptance study conducted among 88 families (divided into four groups), six families complained of irritation of the skin and mucous membranes. Of these reports, one was from the placebo group (using untreated sheets) and the other five (5/22 = 23%) from families using deltamethrin-treated sheets. All families allocated to permethrin and alphacypermethrin groups declared an appreciation for the intervention and reported no side-effects. Ten of the placebo group disliked the intervention, citing no prevention of mosquito biting as the reason. Side-effects associated with deltamethrin indicate that alphacypermethrin and permethrin are more appropriate first choice insecticides for treatment of sheets and blankets.

Deltamethrin Complex emergency Mosquitoes Alphacypermethrin Chaddars Itching Cotton sheets Adverse side-effects Pyrethroids Malaria prevention Sneezing Vector control Culex Insecticide-treated materials Permethrin Refugees Conflict Disaster Anopheles

Pakistan Afghanistan refugee controlled clinical trial clinical trial impregnated bednet Biological Assay Beds Culex tritaeniorhynchus Anopheles nigerrimus Gossypium hirsutum Anopheles pulcherrimus human Culex pipiens quinquefasciatus Refugees bioassay Diptera Insect Vectors controlled study Malaria mosquito Time Factors comparative study disease carrier Animals Culicidae skin ethnology animal Humans insecticide male female Anopheles stephensi Animalia Article disease control Bites and Stings pyrethroid Bedding and Linens Mosquito Control Insecticides bed Pyrethrins growth, development and aging drug effect time