Semi-field assessment of the BG-Malaria trap for monitoring the African malaria vector, Anopheles arabiensis

Batista, E. P.A., Ngowo, H. S. , Opiyo, M., Shubis, G. K., Meza, F. C., Okumu, F. O. and Eiras, A. E. (2017) Semi-field assessment of the BG-Malaria trap for monitoring the African malaria vector, Anopheles arabiensis. PLoS ONE, 12(10), e0186696. (doi: 10.1371/journal.pone.0186696) (PMID:29045484) (PMCID:PMC5646867)

Abstract

Odour-baited technologies are increasingly considered for effective monitoring of mosquito populations and for the evaluation of vector control interventions. The BG-Malaria trap (BGM), which is an upside-down variant of the widely used BG-Sentinel trap (BGS), has been demonstrated to be effective to sample the Brazilian malaria vector, Anopheles darlingi. We evaluated the BGM as an improved method for sampling the African malaria vectors, Anopheles arabiensis. Experiments were conducted inside a large semi-field cage to compare trapping efficiencies of BGM and BGS traps, both baited with the synthetic attractant, Ifakara blend, supplemented with CO2. We then compared BGMs baited with either of four synthetic mosquito lures, Ifakara blend, Mbita blend, BG-lure or CO2, and an unbaited BGM. Lastly, we compared BGMs baited with the Ifakara blend dispensed via either nylon strips, BG cartridges (attractant-infused microcapsules encased in cylindrical plastic cartridge) or BG sachets (attractant-infused microcapsules encased in plastic sachets). All tests were conducted between 6P.M. and 7A.M., with 200–600 laboratory-reared An. arabiensis released nightly in the test chamber. The median number of An. arabiensis caught by the BGM per night was 83, IQR:(73.5–97.75), demonstrating clear superiority over BGS (median catch = 32.5 (25.25–37.5)). Compared to unbaited controls, BGMs baited with Mbita blend caught most mosquitoes (45 (29.5–70.25)), followed by BGMs baited with CO2 (42.5 (27.5–64)), Ifakara blend (31 (9.25–41.25)) and BG lure (16 (4–22)). BGM caught 51 (29.5–72.25) mosquitoes/night, when the attractants were dispensed using BG-Cartridges, compared to BG-Sachet (29.5 (24.75–40.5)), and nylon strips (27 (19.25–38.25)), in all cases being significantly superior to unbaited controls (p < 000.1). The findings demonstrate potential of the BGM as a sampling tool for African malaria vectors over the standard BGS trap. Its efficacy can be optimized by selecting appropriate odour baits and odour-dispensing systems.

• Item Type: Articles
• Additional Information: EPAB was funded by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) (Grant 88881.133584/2016-01) and AEE funded by the Conselho Nacional de Desenvolvimento Científico e Tecnológico of the Ministério da Ciência, Tecnologia e Inovação (CNPq/MCTI) (Grant 310205/2014-0) and Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) (Grant PPM-00502-15). FOO was funded by a Visiting Researcher Fellowship from CNPq/MCTI, (Grant 42070/2013-2) and a Wellcome Trust Intermediate Research Fellowship (Grant WT102350/Z/13/Z).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Ngowo, Halfan and Okumu, Professor Fredros
• Authors: Batista, E. P.A., Ngowo, H. S., Opiyo, M., Shubis, G. K., Meza, F. C., Okumu, F. O., and Eiras, A. E.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: PLoS ONE
• Publisher: Public Library of Science
• ISSN: 1932-6203
• ISSN (Online): 1932-6203
• Copyright Holders: Copyright © 2017 Batista et al.
• First Published: First published in PLoS ONE 12(10): e0186696
• Publisher Policy: Reproduced under a Creative Commons license