Comparative field evaluation of permethrin and deet-treated military uniforms for personal protection against ticks (Acari).

The effectiveness of permethrin-impregnated (PI) versus permethrin-sprayed (PS) military battle dress uniforms was evaluated in protecting soldiers from tick bite. At the same time, an extended-duration formulation of N,N-diethyl-m-toluamide (deet), when applied to clothing only, was evaluated and compared with the permethrin-treated uniforms. Testing consisted of exposing subjects, clothed in either untreated or the variously treated uniforms, to field populations of ticks during a series of 30-min field trials over a period of 21 d during July and August 1988. Permethrin, applied as either a spray (0.5% [AI]), or as an impregnant (0.125% [AI]/cm2), was more effective than deet (33.25% [AI]) applied to clothing only in protecting individuals from tick bite. The mean numbers of ticks on deet-treated, PI, and PS uniforms were 60, 97, and 98% lower, respectively, than on untreated uniforms against all encountered life stages of Amblyomma americanum (L), Dermacentor variabilis (Say), and Ixodes dammini Spielman, Clifford, Piesman and Corwin.