Permethrin-treated chaddars and top-sheets: appropriate technology for protection against malaria in Afghanistan and other complex emergencies

Abstract

Insecticide-treated mosquito nets (ITN) provide excellent protection against malaria; however, they have a number of shortcomings that are particularly evident in politically unstable countries or countries at war: not everyone at risk can necessarily afford a net, nets may be difficult to obtain or import, nets may not be suitable for migrants or refugees sleeping under tents or plastic shelter. There is a need to develop cheaper, locally appropriate alternatives for the most impoverished and for victims of complex emergencies. Afghan women, in common with many Muslim peoples of Asia, wear a veil or wrap known as a chaddar to cover the head and upper body. This cloth doubles as a sheet at night, when they are used by both sexes. A randomized controlled trial was undertaken in which 10% of the families of an Afghan refugee camp (population 3950) in north-western Pakistan had their chaddars and top-sheets treated with permethrin insecticide at a dosage of 1 g/m2 while a further 10% had their chaddars treated with placebo formulation. Malaria episodes were recorded by passive case detection at the camp's health centre. From August to November the odds of having a falciparum or vivax malaria episode were reduced by 64% in children aged 0-10 years and by 38% in refugees aged < 20 years in the group using permethrin-treated chaddars and top-sheets. Incidence in refugees over 20 years of age was not significantly reduced. The cost of the permethrin treatment per person protected (US$0.17) was similar to that for treating bednets (and cost only 10-20% of the price of a new bednet). An entomological study simulating real-life conditions indicated that host-seeking mosquitoes were up to 70% less successful at feeding on men sleeping under treated chaddars and some were killed by the insecticide. Permethrin-treated top-sheets and blankets should provide appropriate and effective protection from malaria in complex emergencies. In Islamic and non-Islamic countries in Asia, treated chaddars and top-sheets should offer a satisfactory solution for the most vulnerable who cannot afford treated nets.

Long-Lasting Permethrin-Impregnated Clothing Protects Against Mosquito Bites in Outdoor Workers

“…In field studies, selfimpregnation of clothing with permethrin was protective against disease in short-term studies, [10][11][12] but not in long term. 13 LLPI clothing has been previously shown to be effective in laboratory settings 5 and to retain mosquito knockdown efficacy for up to 20 washes.…”

“…In one large study, impregnated clothing, sheets, and other materials protected against malaria when used for 16 weeks. 10 Two other smaller short-term studies were done-one showed an effect 11 and one did not. 12 Finally, in the only long-term study (13 months), no effect on the incidence of infection was seen.…”

Child health in complex emergencies

“…23 In Afghanistan, permethrin-treated Islamic cloth wraps (chaddars) used to sleep in and top-sheets reduced the odds of an episode of malaria by 64% in children younger than 10 years, at a cost of US$ 0.17 per person protected. 24 Deltamethrin-treated plastic tarpaulins in Afghan refugee camps effectively killed mosquitoes for prolonged periods. 25 …”

Randomized, Double-Blind, Placebo-Controlled Trial of Monthly versus Bimonthly Dihydroartemisinin-Piperaquine Chemoprevention in Adults at High Risk of Malaria

“…In areas of a low, unstable intensity of transmission, people of all ages are affected, but malaria is a particular problem in those who are exposed to the disease because of their occupations. Interventions that have been proposed to reduce the risk of malaria in these high-risk groups include impregnated nets (7), hammocks (13), and other materials (2,3,8); insect repellents (9); and continuous antimalarial chemoprophylaxis. An alternative approach, developed originally for pregnant women in areas of high intensity of stable transmission, is the administration of an antimalarial treatment dose at regular intervals to exposed individuals, irrespective of parasitemia.…”