Journal of Vector Borne Diseases (Mar 2010)
Laboratory and semi-field evaluation of long-lasting insecticidal nets against leishmaniasis vector, Phlebotomus (Phlebotomus) duboscqi in Kenya
Abstract
Background & objectives: Phlebotomine sandflies are vectors of leishmaniases and other diseases.Long-lasting insecticidal nets (LLINs) as possible tools for control have not been widely testedagainst them. The objective of this study was to determine the efficacy of Olyset® Net and PermaNet®LLINs alongside a local brand, K-O Tab® treated net (Supanet) against Phlebotomus duboscqifemale sandflies.Methods: Four replicates of unwashed and 20x washed Olyset Nets and PermaNets, K-O Tabtreatedand untreated Supanet and ‘no net’ treatments were evaluated against sandflies within thelaboratory by tunnel tests and in semi-field conditions in the greenhouse model for their efficacy.Results: All bednets allowed entry of P. duboscqi sandflies and subsequent blood-feeding. Olysetnet’s blood feeding inhibition was significantly higher than that of Supanet in the laboratory butnot in semi-field condition. Of the LLINs, only Olyset net had sandflies that could not feedsignificantly more than those of Supanet. Additionally, no significant efficacy difference wasobserved between LLINs washed 20x and unwashed ones. The only significant difference noted innumber of sandflies that were found dead or paralyzed within bednets in the semi-field conditionwas between Olyset and K-O Tab treated Supanet. In the laboratory, unwashed Olyset had asignificantly higher number of sandflies killed than all other bednet treatments.Conclusion: Olyset net use in areas where sandflies are nuisance biters and/or disease vectorscould be more beneficial in preventing sandfly bites than other tested bednets. It is recommendedthat mesh sizes of LLINs should be smaller for control of sandflies than those used for control ofmosquitoes.
