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Mwanga EP, Mmbando AS, Mrosso PC, Stica C, Mapua SA, Finda MF, Kifungo K, Kafwenji A, Monroe AC, Ogoma SB, Ngowo HS, Okumu FO. Eave ribbons treated with transfluthrin can protect both users and non-users against malaria vectors. Malar J 2019; 18:314. [PMID: 31533739 PMCID: PMC6751741 DOI: 10.1186/s12936-019-2958-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 09/11/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Eave ribbons treated with spatial repellents effectively prevent human exposure to outdoor-biting and indoor-biting malaria mosquitoes, and could constitute a scalable and low-cost supplement to current interventions, such as insecticide-treated nets (ITNs). This study measured protection afforded by transfluthrin-treated eave ribbons to users (personal and communal protection) and non-users (only communal protection), and whether introducing mosquito traps as additional intervention influenced these benefits. METHODS Five experimental huts were constructed inside a 110 m long, screened tunnel, in which 1000 Anopheles arabiensis were released nightly. Eave ribbons treated with 0.25 g/m2 transfluthrin were fitted to 0, 1, 2, 3, 4 or 5 huts, achieving 0, 20, 40, 60, 80 and 100% coverage, respectively. Volunteers sat near each hut and collected mosquitoes attempting to bite them from 6 to 10 p.m. (outdoor-biting), then went indoors to sleep under untreated bed nets, beside which CDC-light traps collected mosquitoes from 10 p.m. to 6 a.m. (indoor-biting). Caged mosquitoes kept inside the huts were monitored for 24 h-mortality. Separately, eave ribbons, UV-LED mosquito traps (Mosclean) or both the ribbons and traps were fitted, each time leaving the central hut unfitted to represent non-user households and assess communal protection. Biting risk was measured concurrently in all huts, before and after introducing interventions. RESULTS Transfluthrin-treated eave ribbons provided 83% and 62% protection indoors and outdoors respectively to users, plus 57% and 48% protection indoors and outdoors to the non-user. Protection for users remained constant, but protection for non-users increased with eave ribbons coverage, peaking once 80% of huts were fitted. Mortality of mosquitoes caged inside huts with eave ribbons was 100%. The UV-LED traps increased indoor exposure to users and non-users, but marginally reduced outdoor-biting. Combining the traps and eave ribbons did not improve user protection relative to eave ribbons alone. CONCLUSION Transfluthrin-treated eave ribbons protect both users and non-users against malaria mosquitoes indoors and outdoors. The mosquito-killing property of transfluthrin can magnify the communal benefits by limiting unwanted diversion to non-users, but should be validated in field trials against pyrethroid-resistant vectors. Benefits of the UV-LED traps as an intervention alone or alongside eave ribbons were however undetectable in this study. These findings extend the evidence that transfluthrin-treated eave ribbons could complement ITNs.
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Affiliation(s)
- Emmanuel P Mwanga
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Morogoro, Tanzania.
| | - Arnold S Mmbando
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Morogoro, Tanzania
| | - Paul C Mrosso
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Morogoro, Tanzania
| | - Caleb Stica
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Morogoro, Tanzania
| | - Salum A Mapua
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Morogoro, Tanzania
| | - Marceline F Finda
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Morogoro, Tanzania
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Khamis Kifungo
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Morogoro, Tanzania
| | - Andrew Kafwenji
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Morogoro, Tanzania
| | - April C Monroe
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Morogoro, Tanzania
- Johns Hopkins Center for Communication Programs, Baltimore, MD, USA
- University of Basel, Basel, Switzerland
- Swiss Tropical and Public Health Institute (Swiss TPH), Basel, Switzerland
| | - Sheila B Ogoma
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Morogoro, Tanzania
| | - Halfan S Ngowo
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Morogoro, Tanzania
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Fredros O Okumu
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Morogoro, Tanzania
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
- School of Public Health, University of Witwatersrand, Johannesburg, South Africa
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Abstract
Rural-urban comparisons have identified higher age-, race-, and sex-adjusted cancer incidence and mortality rates in urban populations for most anatomic sites, suggesting that rural populations are at lower risk from cancer. Conversely, findings that rural cancer patients are diagnosed at later stages of disease, that higher proportions of rural cancer cases are unstaged at diagnosis, and that rural cancer patients are at a more advanced stage of illness when referred to home health care agencies, suggest that rural cancer patients are disadvantaged when compared to their urban counterparts. This paper summarizes rural-urban patterns of cancer mortality, incidence, and survivorship since 1950; outlines rural-urban differences in utilization of health care services; questions the appropriateness of using rural-urban comparisons of cancer mortality and incidence to evaluate access to cancer care; and suggests potential approaches to the question of whether rural residents have access to cancer care comparable to that available to urban residents.
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Affiliation(s)
- A C Monroe
- North Carolina Rural Health Research Program, University of North Carolina, Chapel Hill 27599
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