Experimental hut evaluation of a novel long-lasting non-pyrethroid durable wall lining for control of pyrethroid-resistant Anopheles gambiae and Anopheles funestus in Tanzania

Malaria Journal

Research

Sophie Weston¹  Louisa A. Messenger¹  Richard M. Oxborough¹  Mark W. Rowland¹  Franklin W. Mosha²  Basiliana Emidi²  Joseph P. Mugasa³  Wema Sudi³  Bernard Batengana³  William Kisinza³  George Mtove³  Robert Malima⁴ 

[1] Department of Disease Control, London School of Hygiene and Tropical Medicine (LSHTM), London, UK;Department of Entomology and Parasitology, Kilimanjaro Christian Medical University College (KCMUCo) of Tumaini University, Moshi, Kilimanjaro, Tanzania;National Institute for Medical Research, Amani Research Centre, Muheza, Tanzania;National Institute for Medical Research, Amani Research Centre, Muheza, Tanzania;Department of Entomology and Parasitology, Kilimanjaro Christian Medical University College (KCMUCo) of Tumaini University, Moshi, Kilimanjaro, Tanzania;

关键词: Insecticide-treated wall lining;    Long-lasting insecticidal nets;    Malaria control;    Experimental huts;    Pyrethroid resistance;   

DOI  :  10.1186/s12936-017-1710-6

 received in 2016-12-08, accepted in 2017-01-21,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundA novel, insecticide-treated, durable wall lining (ITWL), which mimics indoor residual spraying (IRS), has been developed to provide prolonged vector control when fixed to the inner walls of houses. PermaNet® ITWL is a polypropylene material containing non-pyrethroids (abamectin and fenpyroximate) which migrate gradually to the surface.MethodsAn experimental hut trial was conducted in an area of pyrethroid-resistant Anopheles gambiae s.l. and Anopheles funestus s.s. to compare the efficacy of non-pyrethroid ITWL, long-lasting insecticidal nets (LLIN) (Interceptor®), pyrethroid ITWL (ZeroVector®), and non-pyrethroid ITWL + LLIN.ResultsThe non-pyrethroid ITWL produced relatively low levels of mortality, between 40–50% for An. funestus and An. gambiae, across all treatments. Against An. funestus, the non-pyrethroid ITWL when used without LLIN produced 47% mortality but this level of mortality was not significantly different to that of the LLIN alone (29%, P = 0.306) or ITWL + LLIN (35%, P = 0.385). Mortality levels for An. gambiae were similar to An. funestus with non-pyrethroid ITWL, producing 43% mortality compared with 26% for the LLIN. Exiting rates from ITWL huts were similar to the control and highest when the LLIN was present. An attempt to restrict mosquito access by covering the eave gap with ITWL (one eave open vs four open) had no effect on numbers entering. The LLIN provided personal protection when added to the ITWL with only 30% blood-fed compared with 69 and 56% (P = 0.001) for ITWL alone. Cone bioassays on ITWL with 30 min exposure after the trial produced mortality of >90% using field An. gambiae.ConclusionsDespite high mortality in bioassays, the hut trial produced only limited mortality which was attributed to pyrethroid resistance against the pyrethroid ITWL and low efficacy in the non-pyrethroid ITWL. Hut ceilings were left uncovered and may have served as a potential untreated refuge. By analogy to IRS campaigns, which also do not routinely treat ceilings, high community coverage with ITWL may still reduce malaria transmission. Restriction of eave gaps by 75% proved an inadequate barrier to mosquito entry. The findings represent the first 2 months after installation and do not necessarily predict long-term efficacy.

【 授权许可】

CC BY   
© The Author(s) 2017