Am J

The repellency and insecticidal efficacy of Nopikex®, a soap formulation containing 20% diethyl toluamide and 0.5% permethrin, was evaluated against a laboratory colony of phlebotomine sand flies (Lutzomya longipalpis). The repellency of Nopikex soap was also compared with that of a placebo soap against another species (Lu. Youngi) in a forest near Tulua, Valle del Cauca, Colombia. In laboratory trials of the soap, no reduction in repellency was seen 4 hr after application, but within 8 hr, repellency decreased significantly to 67.0% of the initial value (P<0.05) based on calculations of the coefficient of protection (CP). Under field conditions, the soap gave up to 100% protection immediately after application, but within 4 hours its CP value had decreased to a median value of only 44.3%. The placebo soap was also found to be somewhat repellent when compared with no treatment, giving a median CP value of 67.7 immediately after application. No significant mortality was seen in sand flies within 24 hr of exposure to the soap in the laboratory, even in those that had fed on protected volunteers. As the only known vectors of Leishmania, phlebotomine sand flies (Diptera: Psychodidae) are of considerable public health importance in the neotropics, where cutaneous leishmaniasis is acquired principally in rural occupational situations or in areas where human dwellings are surrounded by forest. Most New World sand flies of the genus Lutzomyia do not breed in periurban situations and have a relatively low propensity to enter houses compared with their Old Word relatives (genus Phlebotomus). While this ensures that autochthonous urban leishmaniasis is almost unknown in the Americas, transmission of Leishmania in rural foci is harder to prevent. The breeding sites of vectors are generally difficult to locate, and the diurnal resting sites of the adults may also be hard to find or possess physical characteristics not conducive to spraying with residual insecticides. For the above reasons, measures taken to combat leishmaniasis in the New World are generally restricted to diagnosis and treatment of the disease rather than control of the vectors. Treatment is somewhat costly and requires a series of daily or twice daily injections of Glucantime (Rhone Poulenc, Paris, France) or another pentavalent antimonial that must be given by properly trained personnel. As such, chemotherapy is often impractical, particularly if the patient has to travel long distances and take time off from work to be treated. The pentavalent antimonials are among the safest drugs in current use. Only two deaths have been attributed to these compounds in 40years of