ARS | Publication request: BITING-DETERRENT ACTIVITY OF A DEET ANALOG, TWO DEPA ANALOGS AND SS220 APPLIED TOPICALLY TO HUMAN VOLUNTEERS COMPARED WITH DEET AGAINST THREE SPECIES OF BLOOD-FEEDING FLIES.

Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 10, 2006
Publication Date: November 1, 2006
Citation: Klun, J.A., Khrimian, A., Rowton, E., Kramer, M.H., Debboun, M. 2006. Biting-deterrent activity of a deet analog, two depa analogs and ss220 applied topically to human volunteers compared with deet against three species of blood-feeding flies. Journal of Medical Entomology. 43:1248-1251.

Interpretive Summary: The development of new chemicals for application to human skin to deter disease carrying flies, ticks and other arthropods from biting humans is a difficult task. Using human volunteers, we evaluated the biting deterrent activity of three new candidate compounds applied to skin of human volunteers. Our results indicated that the three compounds were not as effective as Deet in deterring insect bites on humans. This information was sufficient to decide that the newly discovered candidate compounds did not merit further research and development. This information will be used by other industry and federal scientist interested in developing new compounds against biting insects.

Technical Abstract: From an earlier in vitro screening of seventeen N,N-diethyl-3-methylbenzamide (Deet) and N,N-diethylphenylacetamide (DEPA) analogs, two DEPA analogs, N,N-diethyl(3-bromophenyl)acetamide (DM 34), N,N-diethyl[(',','-trifluoro-m-tolyl)]acetamide (DM 156) and Deet analog, N,N,-diethyl[3-(trifluoromethyl)]benzamide (DM 159) were determined to have biting-deterrent activities that were significantly greater than Deet against Aedes aegypti (L.) and Anopheles stephensi Liston. In the present in vivo K & D Module study, the analogs were applied topically to the skin of human volunteers at 24 nmol compound/cm2 skin and compared to the activity of Deet and SS220 at the same skin dose against biting by Ae. aegypti, An. stephensi, and Phlebotomus papatasi Scopoli females. Contrary to previous in vitro tests, results with humans showed that none of the analogs performed more effectively than Deet against the three insects. The study highlights the disparity of behavioral results often seen in moving from in vitro to in vivo testing methods.