title: Insecticide-impregnated netting as a potential tool for long-lasting control of the leishmaniasis vector Lutzomyia longipalpis in animal shelters.
abstract: BACKGROUND
  Leishmaniasis remains a serious neglected disease, with more than 350 million people potentially at risk worldwide. Control strategies often rely on spraying residual insecticides to target populations of the sand fly vectors that transmit Leishmania parasites when blood-feeding. These programmes are often difficult to sustain effectively, as sand fly resting sites must be resprayed on a regular basis. Here, we investigate whether application of insecticide-impregnated netting to a surface could act as an alternative to residual spraying for controlling the American visceral leishmaniasis vector Lutzomyia longipalpis.
  
  
  METHODS
  Female L. longipalpis from our laboratory colony were exposed for 1 h to three treatments applied to plywood surfaces: 2% permethrin-impregnated netting (Olyset®), 20 mg a.i.m-2 micro-encapsulated lambda-cyhalothrin (Demand CS®) and a no-treatment control. We compared the speed at which these treatments acted, by measuring the percentage of sand flies killed both immediately after exposure to the treatment for 1 hour, as well as the number that had died 24 h after the 1 hour exposure. We repeated the experiment at 6 and 12 months following application to test the effectiveness of each treatment over time.
  
  
  RESULTS
  When first applied, the lambda-cyhalothrin killed more sand flies in the first hour than the permethrin-impregnated netting. However, the effectiveness of the lambda-cyhalothrin diminished over time, so that there was no difference between the two treatments at 12 months. Both killed more sand flies than the control. When measured 24 h following exposure, both test treatments had killed close to 100% of sand flies when first applied, but while the lethal effect of the netting was maintained at close to 100% over 12 months, the effectiveness of the residual insecticide diminished to approximately 80% after 6 months.
  
  
  CONCLUSIONS
  The results of these initial laboratory experiments indicate that covering surfaces with insecticide impregnated netting material may provide a longer-lasting solution for killing sand flies than residual spraying. Field trials are needed to identify the feasibility of treating surfaces with netting or similar impregnated materials as part of a control program. In targeting L. longipalpis, the greatest benefits may be seen in treating animal sheds with netting, where these sand flies aggregate in large numbers, and which can be difficult to treat repeatedly by conventional spraying.
authors: Daniel Peter
authors: DP
authors: Bray
authors: James G C
authors: JG
authors: Hamilton
mesh_terms: D000818:Animals; D005260:Female; D007300:Insect Control / Q000379:methods*; D007303:Insect Vectors / Q000187:drug effects*; D057148:Insecticide-Treated Bednets; D007306:Insecticides / Q000494:pharmacology*; D016773:Leishmaniasis, Cutaneous / Q000517:prevention & control* / Q000635:transmission; D009570:Nitriles / Q000494:pharmacology*; D011576:Psychodidae / Q000187:drug effects*; D011722:Pyrethrins / Q000494:pharmacology*; D013997:Time Factors; D014934:Wood
chemical_list: D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; C037304:cyhalothrin
references: J Med Entomol. 1995 Sep;32(5):605-17
references: 7473615
references: Med Vet Entomol. 1997 Jan;11(1):13-24
references: 9061673
references: Trop Med Int Health. 2009 Oct;14(10):1272-7
references: 19772549
references: Parassitologia. 1991 Dec;33 Suppl:399-404
references: 1841235
references: Ann Trop Med Parasitol. 2011 Jan;105(1):31-5
references: 21294947
references: Med Vet Entomol. 1999 May;13(2):191-7
references: 10484165
references: Am J Trop Med Hyg. 1995 Mar;52(3):287-92
references: 7694973
references: Bull World Health Organ. 2004 Feb;82(2):84
references: 15042228
references: Parasit Vectors. 2010 Aug 03;3(1):65
references: 20682050
references: Trans R Soc Trop Med Hyg. 2000 Nov-Dec;94(6):631-6
references: 11198646
references: J Vector Borne Dis. 2010 Mar;47(1):1-10
references: 20231767
references: J Infect Dis. 2002 Nov 1;186(9):1314-20
references: 12402201
references: J Med Entomol. 2009 May;46(3):428-34
references: 19496409
references: Vaccine. 2009 Jul 30;27(35):4747-53
references: 19540273
references: Med Vet Entomol. 1995 Jul;9(3):279-83
references: 7548945
references: Malar J. 2012 Sep 18;11:332
references: 22989007
references: Mem Inst Oswaldo Cruz. 1994 Jul-Sep;89(3):489-95
references: 7476238
references: Annu Rev Entomol. 2013;58:227-50
references: 23317043
references: Med Vet Entomol. 1989 Oct;3(4):441-4
references: 2519695
references: Trans R Soc Trop Med Hyg. 2007 Apr;101(4):360-7
references: 17097698
references: Parasit Vectors. 2010 Mar 11;3:16
references: 20222954
references: Indian J Med Res. 2012 Jul;136(1):22-31
references: 22885260
references: Parasitol Today. 1988 Oct;4(10):270-2
references: 15462999
references: Trans R Soc Trop Med Hyg. 2000 Jul-Aug;94(4):361-6
references: 11127233
references: Trans R Soc Trop Med Hyg. 1999 Nov-Dec;93(6):565-70
references: 10717733
references: Med Vet Entomol. 2003 Mar;17(1):1-18
references: 12680919
references: Acta Trop. 2010 Feb;113(2):162-6
references: 19879851
references: Med Vet Entomol. 2007 Jun;21(2):168-76
references: 17550436
references: BMJ. 2002 Oct 12;325(7368):810-3
references: 12376442
references: PLoS One. 2012;7(9):e44189
references: 23028499
references: Med Vet Entomol. 1994 Jul;8(3):219-24
references: 7949312