potential use of n, diethyl-m-toluamide [deet] as a prophylactic agent in the control of schistosomiasis

ABSTRACT

This work studied the effect of [N, N-diethyl-m-toluamide] DEET on Schistosoma mansoni cercariae viability [in vitro] and skin penetration and migration [in vivo]. DEET concentrations of 30%, 15% and 7.5% were highly efficient in killing all cercariae in vitro within 30, 60 and 240 minutes, respectively. Two concentrations of DEET [15% and 7.5%] were tested separately for their antipenetrant and protective effects in mice by immersing their tails in the drug and then exposed to cercariae, 30 minutes later. It was concluded that DEET [cutaneous application] can be potentially used in the prophylaxis against S. mansoni. The cercaricidal, antipenetrant and protective effects were maximal at a concentration of 15% and resulted in complete protection from infection, which was difficult to achieve with helminthic vaccines. Single application of DEET could effectively protect against schistosomal infection for up to three days and even after two hours water wash. It is recommended to use OFF spray for its dual benefits. The topical use of DEET for protection against schistosomal infection might not be practical for large scale application