Efficacy of the spatial repellent product Mosquito Shield™ against wild pyrethroid-resistant Anopheles arabiensis in south-eastern Tanzania

Malaria Journal

Research

Thomas Michael Mascari¹  Anthony Ortiz¹  Madeleine Rose Chura¹  Hassan Ahamad Ngonyani²  Ummi Abdul Kibondo²  Antony Pius Mseka²  Watson Samuel Ntabaliba²  Alina Celest Soto³  Johnson Kyeba Swai⁴  Sarah Jane Moore⁵ 

[1]S. C. Johnson & Son, Inc., Racine, WI, USA

[2]Vector Control Product Testing Unit, Environmental Health and Ecological Science Department, Ifakara Health Institute, Bagamoyo, Tanzania

[3]Vector Control Product Testing Unit, Environmental Health and Ecological Science Department, Ifakara Health Institute, Bagamoyo, Tanzania

[4]Department of Epidemiology and Public, Health Swiss Tropical and Public Health Institute, Allschwil, Switzerland

[5]Vector Control Product Testing Unit, Environmental Health and Ecological Science Department, Ifakara Health Institute, Bagamoyo, Tanzania

[6]Department of Epidemiology and Public, Health Swiss Tropical and Public Health Institute, Allschwil, Switzerland

[7]University of Basel, Basel, Switzerland

[8]Vector Control Product Testing Unit, Environmental Health and Ecological Science Department, Ifakara Health Institute, Bagamoyo, Tanzania

[9]Department of Epidemiology and Public, Health Swiss Tropical and Public Health Institute, Allschwil, Switzerland

[10]University of Basel, Basel, Switzerland

[11]School of Life Sciences and Bio Engineering, The Nelson Mandela, African Institution of Science and Technology, Tengeru, Arusha, United Republic of Tanzania

关键词: Spatial repellent;    Emanator;    Anopheles;    Pyrethroid;    Transfluthrin;    Experimental hut;   

DOI  :  10.1186/s12936-023-04674-4

 received in 2023-01-30, accepted in 2023-08-13,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundSpatial repellents that create airborne concentrations of an active ingredient (AI) within a space offer a scalable solution to further reduce transmission of malaria, by disrupting mosquito behaviours in ways that ultimately lead to reduced human-vector contact. Passive emanator spatial repellents can protect multiple people within the treated space and can last for multiple weeks without the need for daily user touchpoints, making them less intrusive interventions. They may be particularly advantageous in certain use cases where implementation of core tools may be constrained, such as in humanitarian emergencies and among mobile at-risk populations. The purpose of this study was to assess the efficacy of Mosquito Shield™ deployed in experimental huts against wild, free-flying, pyrethroid-resistant Anopheles arabiensis mosquitoes in Tanzania over 1 month.MethodsThe efficacy of Mosquito Shield™ transfluthrin spatial repellent in reducing mosquito lands and blood-feeding was evaluated using 24 huts: sixteen huts were allocated to Human Landing Catch (HLC) collections and eight huts to estimating blood-feeding. In both experiments, half of the huts received no intervention (control) while the remaining received the intervention randomly allocated to huts and remained fixed for the study duration. Outcomes measured were mosquito landings, blood-fed, resting and dead mosquitoes. Data were analysed by multilevel mixed effects regression with appropriate dispersion and link function accounting for volunteer, hut and day.ResultsLanding inhibition was estimated to be 70% (57–78%) [IRR 0.30 (95% CI 0.22–0.43); p < 0.0001] and blood-feeding inhibition was estimated to be 69% (56–79%) [IRR 0.31 (95% CI 0.21–0.44; p < 0.0001] There was no difference in the protective efficacy estimates of landing and blood-feeding inhibition [IRR 0.98 (95% CI 0.53–1.82; p = 0.958].ConclusionsThis study demonstrated that Mosquito Shield™ was efficacious against a wild pyrethroid-resistant strain of An. arabiensis mosquitoes in Tanzania for up to 1 month and could be used as a complementary or stand-alone tool where gaps in protection offered by core malaria vector control tools exist. HLC is a suitable technique for estimating bite reductions conferred by spatial repellents especially where direct blood-feeding measurements are not practical or are ethically limited.

【 授权许可】

CC BY   
© BioMed Central Ltd., part of Springer Nature 2023

【 图 表 】

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