2.3 Attractive toxic sugar baits (ATSB) for indoor use: The design and evaluation of a novel approach for controlling sand fly vectors of leishmaniasis

London School of Hygiene and Tropical Medicine (LSHTM), London, United Kingdom   - Biogents AG, Regensburg, Germany

Area of research: Prevention
Research programme: Translational Science

Objectives:

(1) To develop an optimal ATSB delivery system for attracting and killing sand flies indoors;

(2) to investigate whether the system is effective against uninfected female sand flies, at different stages of their life history, pyrethroid-resistant sand flies, and Leishmania-infected sand flies, and

(3) determine the optimal ATSB placement strategy for operational use

Expected results:

A suitable novel delivery system will be developed for indoor use against sand flies. Significant effects regarding life stage, resistance status and Leishmania-infection are not expected (but must be investigated). The potential of the tool extends to other vectors of disease such as anopheline mosquitoes.

Summary:

Background: Sand flies require sugar for survival and they preferentially select natural sugar sources . Attempts have been made to exploit sugar-feeding behaviour by using attractive toxic sugar baits (ATSB). When sprayed either on vegetation, or on fences, ATSB are effective against sand flies and mosquitoes. However, their full potential extends beyond outdoor use. Recently, prototype ATSB feeders have been used indoors to kill pyrethroid-resistant mosquitoes and their role in insecticide resistance management was proposed. Likewise, a simple effective tool for controlling sand flies indoors is sought.

Methodology: Prototype ATSB feeders were simply wicks within containers of ATSB solution3. However their efficacy against sand flies has not yet been tested and the delivery system must be improved for domestic use before ATSB is considered a practical vector control method. We propose 2 stages:

I) Development of insecticide/attractant combinations and protope delivery system - investigate different insecticides, sugar compounds (olfactory cues), and feeder designs (optical cues) and select the most attractive combinations.  Evaluate longer-lasting bait formulations, e.g. gels or solids.

II) Free flying rooms/Experimental huts- investigate the behaviour, mortality, blood and sugar feeding of uninfected and infected sand flies around the ATSB stations.  Evaluate the various formats for ATSB: liquids, gels and solids. Establish the optimal number and positioning of ATSB stations around the room/hut.