Bio-efficacy and wash resistance of MAGNet long-lasting insecticidal net against wild populations of Anopheles funestus in experimental huts in Muheza, Tanzania

• Published in: Malaria journal Vol. 18; no. 1; p. 335
• Main Authors: Kweka, Eliningaya J, Tungu, Patrick K, Mahande, Aneth M, Mazigo, Humphrey D, Sayumwe, Subira, Msangi, Shandala, Lyaruu, Lucile, Waweru, John, Kisinza, William, Wangai, James
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 01.10.2019; BioMed Central; BMC
• Subjects: Animals; Anopheles; Anopheles funestus; Care and treatment; Control; Exophily; Experimental hut; Housing; Insecticide Resistance; Insecticide-Treated Bednets; Insecticides; Laundering; MAGNet; Malaria; Medical research; Mortality; Mosquito Control - instrumentation; Permethrin; Pyrethrins; Resistance; Risk factors; Tanzania; Tanzania; MAGNet; Resistance; Experimental hut; Anopheles funestus; Exophily; Mortality; LLINs
• ISSN: 1475-2875; 1475-2875
• DOI: 10.1186/s12936-019-2973-x

The decline in malaria cases and vectors is major milestone in fighting against malaria. The efficacy of MAGNet long-lasting insecticidal nets (MAGNet LLIN), an alpha-cypermethrin incorporated long-lasting net, with the target dose ± 25% of 5.8 g active ingredient (AI)/kg (4.35-7.25 g AI/kg) was evaluated in six veranda-trap experimental huts in Muheza, Tanzania against freely flying wild population of Anopheles funestus. MAGNet LLINs were tested against wild, free-flying, host-seeking An. funestus mosquitoes over a period of 6 weeks (total of 36 nights in the huts). MAGNet LLIN efficacy was determined in terms of mosquito mortality, blood-feeding inhibition, deterrence, induced exiting, personal protection, and insecticidal killing over 20 washes according to WHO standardized procedures. Efficacy was compared with reference to a WHOPES recommended approved LLINs (DuraNet) and to a net conventionally treated (CTN) treated with alpha-cypermethrin at WHO-recommended dose and washed to just before cut-off point. The efficacy of MAGNet was evaluated in experimental huts against wild, free-flying, pyrethroid-resistant An. funestus. The WHO-susceptibility method was used to detect resistance in wild Anopheles exposed to 0.75% permethrin. Mosquito mortality, blood-feeding inhibition and personal protection were compared between untreated nets and standard LLINs. Blood-feeding rates were recorded and compared between the 20 times washed; blood-feeding rates between 20 times washed MAGNet LLIN and 20 times washed WHOPES-approved piperonyl butoxide (PBO)/pyrethroid were not statistically different (p > 0.05). The results have evidently shown that MAGNet LLIN provides similar blood-feeding inhibition, exophily, mortality, and deterrence to the standard approved LLIN, thus meeting the WHOPES criteria for blood feeding. The significantly high feeding inhibition and personal protection over pyrethroid-resistant An. funestus recorded by both unwashed and 20 times washed MAGNet compared to the unwashed DuraNet, the WHOPES-approved standard pyrethroid-only LLIN provides proof of MAGNet meeting Phase II WHOPES criteria for a LLIN. Based on this study, MAGNet has been shown to have a promising impact on protection when 20 times washed against a highly resistant population of An. funestus.