The contribution of sandfly control to leishmaniasis control.

Without doubt the single most important constraint on assessing the value of vector control in leishmaniasis control is the lack of well documented examples of intervention; information is usually anecdotal and therefore it is simply not possible to evaluate precisely the significance of sandfly control in disease control. Where the vector is peri-domestic, house spraying with residual insecticides has been employed, but this has usually been as a by-product of anti-malarial control (e.g. N.E.India). Increasing incidence of leishmaniasis following the cessation of mosquito control is cited as evidence of efficacy. However, habitat modification such as the destruction of mammal reservoirs and their burrows, has been effective in arid regions of the Middle East and Central Asia, and forest clearance in combination with insecticides in French Guiana. There have been several imaginative attempts at controlling sandflies by applying insecticides to non-domestic resting sites (eg. emergent trees in rain-forest; termite hills in Kenya and S. Ethiopia) but these have met with varying degrees of success. Fortunately there is little evidence of insecticide resistance. Therefore, there is still scope for exploring control methods based on either the systematic application of insecticides alone, the impregnation of nets or curtains, or even the use of insecticides or chemosterilants in conjunction with an attractant (eg. sugar or pheromones).