Short report: study on the efficacy of a new long-acting formulation of N, N-diethyl-m-toluamide (DEET) for the prevention of tick attachment.

Abstract

Abstract. The beneficial effects of N, N-diethyl-m-toluamide (DEET) against biting insects of human and animals appear to last Ͻ6 hr after a single application to the skin. To prolong the repellent effects of DEET, recently we developed a new long-acting formulation of DEET called LIPODEET. This preparation was retained in the skin for a longer duration of time with minimal systemic absorption. In this study, we have evaluated the protective effect of three compounds (DEET, LIPODEET, and Morpel 220) against attachment of two species of ticks (Amblyomma americanum and Dermacentor variabilis) to rabbit ears. Results show that LIPODEET and Morpel 220 were highly effective in preventing tick attachment to the skin for a longer duration of time (up to 72 hr) than DEET after a single application. Moreover, LIPODEET was found to be acaricidal to both the species of ticks. N, N-diethyl-m-toluamide (DEET) is a safe and broad spectrum insect repellent used extensively against both human and animal pests worldwide. [1][2][3] We previously reported that DEET prevented infections due to the parasite Schistosoma mansoni when applied to the skin of mice. 4 However, the longevity of DEET action on the skin was short-lived, possibly due to rapid absorption of DEET through the skin. 5,6 Although experimental studies have confirmed that DEETrelated toxicity is minimal after systemic absorption, [6][7][8][9] there are a few reports of toxicity associated with the use of DEET in humans and animals especially, if the chemical is misused or the patients are more susceptible after systemic absorption of large quantities of DEET. [10][11][12][13][14] Currently available preparations of DEET are contained in vehicles that inevitably increase the absorption of DEET through the skin. 14 This potentially could increase the risk of DEET-induced toxicity. Therefore, any agent that may retard the systemic absorption of DEET can potentially decrease the DEET-induced toxicity. Several new vehicles have been tried to reduce DEET absorption through the skin with varying success. [15][16][17] Recently, we reported a liposomal preparation of DEET (LI-PODEET) that was exceptionally effective in retaining DEET on the superficial layers of the skin. Subsequent testing showed that LIPODEET prolonged the protective activity of DEET against S. mansoni for up to 72 hr after a single application. 5 Several reports suggest that DEET has some repellency action against ticks. However, compared with other repellents such as permethrin or piperidine, DEET is less effective against ticks and the repellent action of DEET is short lived. [18][19][20][21] Since ticks attach to the skin for feeding and LIPODEET is retained in the skin for a longer duration of time, in this study we wanted to evaluate the potential use of LIPODEET against tick attachment.Adult stages of Amblyomma americanum and Dermacentor variabilis (obtained from Dr. Jerry Bowman, Department of Entomology, Oklahoma State University, Stillwater, OK) were used in these experiments. Three different for...

A sensitive bioassay for spider mite (Tetranychus urticae) repellency: a double bond makes a difference

“…Each of these alarm pheromones contains oxygen, and so they are not hydrocarbons, but their activity demonstrates that mites can perceive volatiles. Similarly, DEET is also an effective tick repellent (Salafsky et al 2000;Schreck et al 1995), as well as an effective insect repellent, an indication that acarids can sense repellents. Consequently there can be little doubt that arthropods can sense hydrocarbons and the present work clearly demonstrates that T. urticae can perceive and respond to hydrocarbons.…”

Tick Bite Protection With Permethrin-Treated Summer-Weight Clothing

“…DEET, along with active ingredients such as Picaridin and other novel compounds, have proven successful against mosquitoes. However, the effectiveness and duration of these compounds to repel ticks are variable, depending on formulation and method of testing (Jensenius et al 2005, Carroll et al 2008, Salafsky et al 2000, Solberg et al 1995). An alternative personal-use repellent strategy, available for decades, is to apply repellent or toxicant products to clothing or other fabrics rather than directly on the skin (Lane and Anderson 1984).…”

Repellent activity of DEET against Amblyomma cajennense (Acari: Ixodidae) nymphs submitted to different laboratory bioassays

“…On the other hand, protections of similar magnitude were not obtained against I. ricinus (STAUB et al, 2002) in field tests or A. hebraeum (PRETORIUS et al, 2003) in fingertip bioassay, even using higher concentrations. Salafsky et al (2000) observed only partial repellency of A. americanum adults using commercial 20% DEET formulations and no protection against Dermacentor variabilis Say. The compound did not repel Amblyomma variegatum Fabricius adults when released with an attractant stimulus (MCMAHON et al, 2003).…”

“…Salafsky et al (2000) observed high mortality of A. americanum and D. variabilis when exposed to LIPODEET, a long-lasting action formulation of DEET, but it was not proved for DEET.…”