Effects of flood irrigation on the risk of selected zoonotic pathogens in an arid and semi-arid area in the eastern Kenya

To investigate the effects of irrigation on land cover changes and the risk of selected zoonotic pathogens, we carried out a study in irrigated, pastoral and riverine areas in the eastern Kenya. Activities implemented included secondary data analyses to determine land use and land cover (LULC) chang...

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Main Authors: Bett, Bernard K., Said, Mohammed Yahya, Sang, R., Bukachi, S., Wanyoike, S., Kifugo, S.C., Otieno, Fredrick T., Ontiri, E., Njeru, I., Lindahl, Johanna F., Grace, Delia
Format: Journal Article
Language:Inglés
Published: Public Library of Science 2017
Subjects:
Online Access:https://hdl.handle.net/10568/81512
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author Bett, Bernard K.
Said, Mohammed Yahya
Sang, R.
Bukachi, S.
Wanyoike, S.
Kifugo, S.C.
Otieno, Fredrick T.
Ontiri, E.
Njeru, I.
Lindahl, Johanna F.
Grace, Delia
author_browse Bett, Bernard K.
Bukachi, S.
Grace, Delia
Kifugo, S.C.
Lindahl, Johanna F.
Njeru, I.
Ontiri, E.
Otieno, Fredrick T.
Said, Mohammed Yahya
Sang, R.
Wanyoike, S.
author_facet Bett, Bernard K.
Said, Mohammed Yahya
Sang, R.
Bukachi, S.
Wanyoike, S.
Kifugo, S.C.
Otieno, Fredrick T.
Ontiri, E.
Njeru, I.
Lindahl, Johanna F.
Grace, Delia
author_sort Bett, Bernard K.
collection Repository of Agricultural Research Outputs (CGSpace)
description To investigate the effects of irrigation on land cover changes and the risk of selected zoonotic pathogens, we carried out a study in irrigated, pastoral and riverine areas in the eastern Kenya. Activities implemented included secondary data analyses to determine land use and land cover (LULC) changes as well as human, livestock and wildlife population trends; entomological surveys to characterize mosquitoes population densities and species distribution by habitat and season; and serological surveys in people to determine the risk of Rift Valley fever virus (RVFV), West Nile fever virus (WNV), dengue fever virus (DFV), Leptospira spp. and Brucella spp. Results demonstrate a drastic decline in vegetation cover over ≈25 years particularly in the irrigated areas where cropland increased by about 1,400% and non-farm land (under closed trees, open to closed herbaceous vegetation, bushlands and open trees) reduced by 30–100%. The irrigated areas had high densities of Aedes mcintoshi, Culex spp. and Mansonia spp. (important vectors for multiple arboviruses) during the wet and dry season while pastoral areas had high densities of Ae. tricholabis specifically in the wet season. The seroprevalences of RVFV, WNV and DFV were higher in the irrigated compared to the pastoral areas while those for Leptospira spp and Brucella spp. were higher in the pastoral compared to the irrigated areas. It is likely that people in the pastoral areas get exposed to Leptospira spp by using water fetched from reservoirs that are shared with livestock and wildlife, and to Brucella spp. by consuming raw or partially cooked animal-source foods such as milk and meat. This study suggests that irrigation increases the risk of mosquito-borne infections while at the same time providing a protective effect against zoonotic pathogens that thrive in areas with high livestock population densities.
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spelling CGSpace815122023-12-08T19:36:04Z Effects of flood irrigation on the risk of selected zoonotic pathogens in an arid and semi-arid area in the eastern Kenya Bett, Bernard K. Said, Mohammed Yahya Sang, R. Bukachi, S. Wanyoike, S. Kifugo, S.C. Otieno, Fredrick T. Ontiri, E. Njeru, I. Lindahl, Johanna F. Grace, Delia epidemiology health zoonoses To investigate the effects of irrigation on land cover changes and the risk of selected zoonotic pathogens, we carried out a study in irrigated, pastoral and riverine areas in the eastern Kenya. Activities implemented included secondary data analyses to determine land use and land cover (LULC) changes as well as human, livestock and wildlife population trends; entomological surveys to characterize mosquitoes population densities and species distribution by habitat and season; and serological surveys in people to determine the risk of Rift Valley fever virus (RVFV), West Nile fever virus (WNV), dengue fever virus (DFV), Leptospira spp. and Brucella spp. Results demonstrate a drastic decline in vegetation cover over ≈25 years particularly in the irrigated areas where cropland increased by about 1,400% and non-farm land (under closed trees, open to closed herbaceous vegetation, bushlands and open trees) reduced by 30–100%. The irrigated areas had high densities of Aedes mcintoshi, Culex spp. and Mansonia spp. (important vectors for multiple arboviruses) during the wet and dry season while pastoral areas had high densities of Ae. tricholabis specifically in the wet season. The seroprevalences of RVFV, WNV and DFV were higher in the irrigated compared to the pastoral areas while those for Leptospira spp and Brucella spp. were higher in the pastoral compared to the irrigated areas. It is likely that people in the pastoral areas get exposed to Leptospira spp by using water fetched from reservoirs that are shared with livestock and wildlife, and to Brucella spp. by consuming raw or partially cooked animal-source foods such as milk and meat. This study suggests that irrigation increases the risk of mosquito-borne infections while at the same time providing a protective effect against zoonotic pathogens that thrive in areas with high livestock population densities. 2017-05-31 2017-06-12T07:22:16Z 2017-06-12T07:22:16Z Journal Article https://hdl.handle.net/10568/81512 en Open Access Public Library of Science Bett, B., Said, M.Y., Sang, R., Bukachi, S., Wanyoike, S., Kifugo, S.C., Otieno, F., Ontiri, E., Njeru, I., Lindahl, J. and Grace, D. 2017. Effects of flood irrigation on the risk of selected zoonotic pathogens in an arid and semi-arid area in the eastern Kenya. PLOS ONE 12(5): e0172626.
spellingShingle epidemiology
health
zoonoses
Bett, Bernard K.
Said, Mohammed Yahya
Sang, R.
Bukachi, S.
Wanyoike, S.
Kifugo, S.C.
Otieno, Fredrick T.
Ontiri, E.
Njeru, I.
Lindahl, Johanna F.
Grace, Delia
Effects of flood irrigation on the risk of selected zoonotic pathogens in an arid and semi-arid area in the eastern Kenya
title Effects of flood irrigation on the risk of selected zoonotic pathogens in an arid and semi-arid area in the eastern Kenya
title_full Effects of flood irrigation on the risk of selected zoonotic pathogens in an arid and semi-arid area in the eastern Kenya
title_fullStr Effects of flood irrigation on the risk of selected zoonotic pathogens in an arid and semi-arid area in the eastern Kenya
title_full_unstemmed Effects of flood irrigation on the risk of selected zoonotic pathogens in an arid and semi-arid area in the eastern Kenya
title_short Effects of flood irrigation on the risk of selected zoonotic pathogens in an arid and semi-arid area in the eastern Kenya
title_sort effects of flood irrigation on the risk of selected zoonotic pathogens in an arid and semi arid area in the eastern kenya
topic epidemiology
health
zoonoses
url https://hdl.handle.net/10568/81512
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