A new clothing impregnation method for personal protection against ticks and biting insects

The efficacy and residual activity of a factory-based, permethrin-impregnated military battle dress uniform (BDU) using a new polymer-coating technique has been evaluated by laboratory and field testing during deployment to Afghanistan and compared with two commercially available, widely used dipping methods. Residual permethrin concentrations and remaining contact toxicities on treated fabrics before laundering, after up to 100 launderings as well as after being worn-out during deployment were tested against Aedes aegypti (L.) and Ixodes ricinus (L.). The residual amount of permethrin was considerably higher with the polymer-coating technique with 280 mg/m2 remaining after 100 launderings. Polymer-coated BDUs collected for disposal after being worn-out during military deployment showed equivalent or better residual knockdown efficacy against test arthropods when compared with the results obtained with the US Army IDA (Illinois Department of Agriculture)-Kit after 50 launderings, which represent the recommended baseline for re-impregantion or disposal of the impregnated fabric. BDUs impregnated by the polymer-coating method were found to be effective throughout the lifetime of the uniform, ensuring protection of soldiers in the field from arthropod vectors, while simultaneously decreasing logistical constraints and occupational health threats.