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Ojianwuna CC, Enwemiwe VN, Egwunyenga AO, Agboro A, Owobu E. Sampling efficiency and screening of Aedes albopictus for yellow fever virus in Niger Delta region of Nigeria. Pan Afr Med J 2024; 47:120. [PMID: 38828420 PMCID: PMC11143074 DOI: 10.11604/pamj.2024.47.120.39462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 03/12/2024] [Indexed: 06/05/2024] Open
Abstract
Introduction Aedes albopictus, like Aedes aegypti, is a virulent vector of arboviruses especially the well-documented spread of yellow fever around the world. Although yellow fever is prevalent in Nigeria, there is a paucity of information in the Niger Delta region on the distribution of Aedes mosquito vectors and molecular detection of the virus in infected mosquitoes. This study sampled Aedes mosquitoes around houses associated with farms from four communities (Otolokpo, Ute-Okpu, Umunede, and Ute Alohen) in Ika North-East Local Government Area of Delta State, Nigeria. Methods various sampling methods were used in Aedes mosquito collection to test their efficacy in the survey. Mosquitoes in holding cages were killed by freezing and morphologically identified. A pool of 15 mosquitoes per Eppendorf tube was preserved in RNAi later for yellow fever virus screening. Two samples were molecularly screened for each location. Results seven hundred and twenty-five (725) mosquitoes were obtained from the various traps. The mean abundance of the mosquitoes was highest in m-HLC (42.9) compared to the mosquitoes sampled using other techniques (p<0.0001). The mean abundance of mosquitoes was lowest in Center for Disease Control (CDC) light traps without attractant (0.29). No yellow fever virus strain was detected in all the mosquitoes sampled at the four locations. Conclusion this study suggests that Aedes albopictus are the mosquitoes commonly biting around houses associated with farms. More so, yellow fever virus was not detected in the mosquitoes probably due to the mass vaccination exercise that was carried out the previous year in the study area. More studies are required using the m-HLC to determine the infection rate in this endemic area.
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Affiliation(s)
- Chioma Cynthia Ojianwuna
- Department of Animal and Environmental Biology, Faculty of Science, Delta State University, Abraka, Nigeria
| | - Victor Ngozi Enwemiwe
- Department of Animal and Environmental Biology, Faculty of Science, Delta State University, Abraka, Nigeria
| | - Andy Ogochukwu Egwunyenga
- Department of Animal and Environmental Biology, Faculty of Science, Delta State University, Abraka, Nigeria
| | - Akwilla Agboro
- Department of Animal and Environmental Biology, Faculty of Science, Delta State University, Abraka, Nigeria
| | - Emmanuel Owobu
- Department of Animal and Environmental Biology, Faculty of Science, Delta State University, Abraka, Nigeria
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Carnaghi M, Mandelli F, Feugère L, Joiner J, Young S, Belmain SR, Hopkins RJ, Hawkes FM. Visual and thermal stimuli modulate mosquito-host contact with implications for improving malaria vector control tools. iScience 2024; 27:108578. [PMID: 38155768 PMCID: PMC10753043 DOI: 10.1016/j.isci.2023.108578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 10/23/2023] [Accepted: 11/23/2023] [Indexed: 12/30/2023] Open
Abstract
Malaria prevention relies on mosquito control interventions that use insecticides and exploit mosquito behavior. The rise of insecticide resistance and changing transmission dynamics urgently demand vector control innovation. To identify behavioral traits that could be incorporated into such tools, we investigated the flight and landing response of Anopheles coluzzii to human-like host cues. We show that landing rate is directly proportional to the surface area of thermal stimulus, whereas close-range orientation is modulated by both thermal and visual inputs. We modeled anopheline eye optics to theorize the distance at which visual targets can be detected under a range of conditions, and experimentally established mosquito preference for landing on larger targets, although landing density is greater on small targets. Target orientation does not affect landing rate; however, vertical targets can be resolved at greater distance than horizontal targets of the same size. Mosquito traps for vector control could be significantly enhanced by incorporating these features.
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Affiliation(s)
- Manuela Carnaghi
- Department of Agriculture, Health, and Environment, Natural Resources Institute, University of Greenwich at Medway, Chatham, Kent, ME4 4TB, UK
- School of Science, University of Greenwich at Medway, Chatham, Kent, ME4 4TB, UK
| | | | - Lionel Feugère
- Department of Agriculture, Health, and Environment, Natural Resources Institute, University of Greenwich at Medway, Chatham, Kent, ME4 4TB, UK
| | - Jillian Joiner
- Department of Agriculture, Health, and Environment, Natural Resources Institute, University of Greenwich at Medway, Chatham, Kent, ME4 4TB, UK
| | - Stephen Young
- Department of Agriculture, Health, and Environment, Natural Resources Institute, University of Greenwich at Medway, Chatham, Kent, ME4 4TB, UK
| | - Steven R. Belmain
- Department of Agriculture, Health, and Environment, Natural Resources Institute, University of Greenwich at Medway, Chatham, Kent, ME4 4TB, UK
| | - Richard J. Hopkins
- Department of Agriculture, Health, and Environment, Natural Resources Institute, University of Greenwich at Medway, Chatham, Kent, ME4 4TB, UK
| | - Frances M. Hawkes
- Department of Agriculture, Health, and Environment, Natural Resources Institute, University of Greenwich at Medway, Chatham, Kent, ME4 4TB, UK
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Kathet S, Sudi W, Mwingira V, Tungu P, Aalto M, Hakala T, Honkala M, Malima R, Kisinza W, Meri S, Khattab A. Efficacy of 3D screens for sustainable mosquito control: a semi-field experimental hut evaluation in northeastern Tanzania. Parasit Vectors 2023; 16:417. [PMID: 37964334 PMCID: PMC10647037 DOI: 10.1186/s13071-023-06032-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 10/24/2023] [Indexed: 11/16/2023] Open
Abstract
BACKGROUND A three-dimensional window screen (3D-Screen) has been developed to create a window double-screen trap (3D-WDST), effectively capturing and preventing the escape of mosquitoes. A 2015 laboratory study demonstrated the 3D-Screen's efficacy, capturing 92% of mosquitoes in a double-screen setup during wind tunnel assays. To further evaluate its effectiveness, phase II experimental hut trials were conducted in Muheza, Tanzania. METHODS Three experimental hut trials were carried out between 2016 and 2017. Trial I tested two versions of the 3D-WDST in huts with open or closed eaves, with one version using a single 3D-Screen and the other using two 3D-Screens. Trial II examined the 3D-WDST with two 3D-Screens in huts with or without baffles, while Trial III compared handmade and machine-made 3D structures. Mosquito capturing efficacy of the 3D-WDST was measured by comparing the number of mosquitoes collected in the test hut to a control hut with standard exit traps. RESULTS Trial I showed that the 3D-WDST with two 3D-Screens used in huts with open eaves achieved the highest mosquito-capturing efficacy. This treatment captured 33.11% (CI 7.40-58.81) of female anophelines relative to the total collected in this hut (3D-WDST and room collections) and 27.27% (CI 4.23-50.31) of female anophelines relative to the total collected in the control hut (exit traps, room, and verandahs collections). In Trial II, the two 3D-Screens version of the 3D-WDST captured 70.32% (CI 56.87-83.77) and 51.07% (CI 21.72-80.41) of female anophelines in huts with and without baffles, respectively. Compared to the control hut, the capturing efficacy for female anophelines was 138.6% (37.23-239.9) and 42.41% (14.77-70.05) for huts with and without baffles, respectively. Trial III demonstrated similar performance between hand- and machine-made 3D structures. CONCLUSIONS The 3D-WDST proved effective in capturing malaria vectors under semi-field experimental hut conditions. Using 3D-Screens on both sides of the window openings was more effective than using a single-sided 3D-Screen. Additionally, both hand- and machine-made 3D structures exhibited equally effective performance, supporting the production of durable cones on an industrial scale for future large-scale studies evaluating the 3D-WDST at the community level.
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Affiliation(s)
- Subam Kathet
- Department of Bacteriology and Immunology, Haartman Institute, and Translational Immunology Research Program, University of Helsinki, 00014, Helsinki, Finland
| | - Wema Sudi
- Amani Medical Research Centre, National Institute for Medical Research, Muheza, Tanzania
| | - Victor Mwingira
- Amani Medical Research Centre, National Institute for Medical Research, Muheza, Tanzania
| | - Patrick Tungu
- Amani Medical Research Centre, National Institute for Medical Research, Muheza, Tanzania
| | | | - Tomi Hakala
- Department of Materials Science, Tampere University of Technology, P.O. Box 589, 33101, Tampere, Finland
| | - Markku Honkala
- Department of Materials Science, Tampere University of Technology, P.O. Box 589, 33101, Tampere, Finland
| | - Robert Malima
- Amani Medical Research Centre, National Institute for Medical Research, Muheza, Tanzania
| | - William Kisinza
- Amani Medical Research Centre, National Institute for Medical Research, Muheza, Tanzania
| | - Seppo Meri
- Department of Bacteriology and Immunology, Haartman Institute, and Translational Immunology Research Program, University of Helsinki, 00014, Helsinki, Finland
- HUSLAB Diagnostic Center, Helsinki University Central Hospital, N00029, Helsinki, Finland
| | - Ayman Khattab
- Department of Bacteriology and Immunology, Haartman Institute, and Translational Immunology Research Program, University of Helsinki, 00014, Helsinki, Finland.
- Department of Nucleic Acid Research, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, New Borg El-Arab City, 21934, Alexandria, Egypt.
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