Evaluation of the sensitivity of Aedes aegypti and Anopheles gambiae complex mosquitoes to two insect repellents: DEET and KBR 3023

Abstract

SummaryWe conducted laboratory tests to assess the sensitivity to the insect repellent 1-piperidinecarboxylic acid, 2-(2-hydroxyethyl)-, 1-methylpropylester (known as KBR 3023 or Picaridin, trade name Bayrepel Ò ) of West African strains of the yellow fever mosquito Aedes aegypti and of malaria vectors of the Anopheles gambiae complex, in comparison with the standard repellent N,N-diethyl-3-methylbenzamide (DEET). Test mosquitoes were exposed according to a 'separate arms' protocol to logarithmic dose increments applied on one arm of human subjects to evaluate the relative potency, and the median effective dosages (ED 50 and ED 90 ). According to a logistic regression model fitted to the experimental data, the dose-response relationship for the two repellents was the same within each species, thus pooled ED values were assessed for each mosquito separately. The median ED of KBR 3023 and DEET was estimated at 0.78 (95% confidence limits (CI): 0.57-1.04) and at 0.018 lg/cm 2 (0.004-0.052) for mosquitoes of the An. gambiae complex and Ae. aegypti, respectively. ED 90 values were 125.6 (81.4-201.3) and 24.0 lg/cm 2 (5.7-208.5) for An. gambiae s.l. and Ae. aegypti, respectively. The relative potency of KBR 3023 was not significantly different from that of DEET for An. gambiae s.l. (95% confidence limits 0.7-1.0), whereas in the case of Ae. aegypti it was with 95% probability 1.1-2.0 times more potent than DEET. On the basis of available evidence, KBR 3023 represents a promising alternative to DEET for personal protection against bites of these important vectors of disease in the Afrotropical region.

Prevention of Malaria in Long-term Travelers

“…29 Some recent studies have found picaridin, DEET, and PMD effective against Anopheles mosquitoes [30][31][32][33][34][35][36][37] (TABLE 2). Because picaridin has a longer halflife after application on skin, it may be particularly useful in areas with high vector densities.…”

Design of formulated products: A systematic methodology

“…DEET has been shown to be aggressive on clothes, plastics, glasses, and to have a high potential to irritate eyes and skin. 39 It has also been blamed to be sticky, greasy and with an unpleasant odor. Finally, it causes systemic and local toxicities.…”

“…It is far superior to DEET in terms of safety, toxicology, material compatibility and cosmetic properties. 39 Picaridin was selected as the AI in this formulated product. Subtask S1-D2.3: AIs properties.…”

Design of formulated products: Experimental component

“…Only one AI is necessary, since the main function of the product is only one: to repel mosquitoes. DEET, 35,36 natural AIs, 37 and Picaridin 35 are usually employed as AIs in insect repellents. Picaridin was selected because of its superior qualities.…”