Topical Insecticide Treatments to Protect Dogs from Sand Fly Vectors of Leishmaniasis

Abstract

We compared the susceptibility of sand fly vectors to four topical insecticide treatments applied to domestic dogs, a reservoir of human leishmaniasis. Dogs were exposed to sand flies pretreatment and at 1 week, 1 month, and 2 months posttreatment. Sand fly bloodfeeding and survival rate of both fed and unfed flies were significantly reduced by the permethrin, deltamethrin, and fenthion treatments, but diazinon had no effect. The survival rate of bloodfed sand flies was reduced by up to 86% with deltamethrin collars. The antifeeding effect suggests that deltamethrin collars may be recommended to dog owners to protect their pets from sandfly-borne diseases. The combined effects on sand fly feeding and survival indicate that epidemiologic, community-based trials are warranted to test whether deltamethrin collars could reduce the incidence of canine and, hence, human leishmaniasis.

Effects of topical application of fipronil spot-on on dogs against the Chagas disease vector Triatoma infestans

“…19 The relative advantages of insecticide collars are that their presence on dogs is proof that the intervention is being applied during a control campaign, and for some collars, the insecticide is continuously discharged over a period of several months. The implementation of any topical insecticide treatment or collars is likely to have the consent of affected rural villagers.…”

Domestic dog ownership in Iran is a risk factor for human infection with Leishmania infantum.

“…Most of these problems are probably intractable, and so alternative control tools for targeting domestic dogs should be sought. 36,37 …”

Leishmaniasis: new approaches to disease control

“…However, a novel method for topical application of insecticide on dogs enables the insecticidal effect to persist for up to eight months. w24 Experimental trials have consistently shown that deltamethrin treated collars (fig 4) reduce by up to 90% the proportion of sandflies that take a blood meal and survive 20. w24 Widespread use of these collars with domestic dogs in Italy reduced their risk of being infected by L infantum , w25 and a matched cluster randomised trial in Iran showed that, not only was the odds of infection in dogs reduced by 54%, but children living in the treated villages had significantly less risk of infection as well (odds ratio 0.57) 21…”

“…Dipping dogs in insecticide w23 or applying topical insecticide lotions20 can substantially reduce sandfly bites on dogs and so protect them from infection, but this strategy requires regular retreatment as the insecticidal effect is short lived. However, a novel method for topical application of insecticide on dogs enables the insecticidal effect to persist for up to eight months.…”