Rift Valley fever (RVF) is an acute mosquito-borne viral zoonosis whose outbreaks are often associated with prolonged rainfall and flooding, during which large numbers of vectors emerge. Recent studies into the inter-epidemic maintenance of RVF virus (RVFV) suggest that both vertical transmission in vectors and direct transmission between hosts act in combination with predisposing factors for persistence of the virus. A comparative longitudinal survey was carried out in Tana River County, Kenya, in irrigated, riverine and pastoral ecosystems from September 2014-June 2015. The objectives were to investigate the possibility of low-level RVFV transmission in these ecosystems during an inter-epidemic period (IEP), examine variations in RVFV seroprevalence in sheep and goats and determine the risk factors for transmission. Three hundred and sixteen small ruminants were selected and tested for immunoglobulin G antibodies against RVFV nucleoprotein using a competitive ELISA during six visits. Data on potential risk factors were also captured. Inter-epidemic RVFV transmission was evidenced by 15 seroconversions within the irrigated and riverine villages. The number of seroconversions was not significantly different (OR = 0.66, CI = 0.19-2.17, p = .59) between irrigated and riverine areas. No seroconversions were detected in the pastoral ecosystem. This study highlights the increased risk of inter-epidemic RVFV transmission posed by irrigation, through provision of necessary environmental conditions that enable vectors access to more breeding grounds, resting places and shade, which favour their breeding and survival.
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http://dx.doi.org/10.1111/tbed.12674 | DOI Listing |
J Hazard Mater
November 2024
School of Geography, Nanjing Normal University, Nanjing 210023, China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China; Key Laboratory of Virtual Geographic Environment, Ministry of Education, Nanjing Normal University, Nanjing 210023, China. Electronic address:
Nitrate (NO) contamination in riverine networks has threatened the environment and human health. Clarifying the NO source and environmental fate within the basin under different underlying surfaces is essential for water body protection, especially China's two mother rivers. A series of combination methods were established i.
View Article and Find Full Text PDFEnviron Sci Technol
November 2024
Department of Environmental Toxicology, University of California─Davis, Davis, California 95616, United States.
Sensors (Basel)
November 2023
Department of Geoinformatics, Physical and Environmental Geography, University of Szeged, 6722 Szeged, Hungary.
Rivers transport terrestrial microplastics (MP) to the marine system, demanding cost-effective and frequent monitoring, which is attainable through remote sensing. This study aims to develop and test microplastic concentration (MPC) models directly by satellite images and indirectly through suspended sediment concentration (SSC) as a proxy employing a neural network algorithm. These models relied upon high spatial (26 sites) and temporal (198 samples) SSC and MPC data in the Tisza River, along with optical and active sensor reflectance/backscattering.
View Article and Find Full Text PDFEnviron Res
December 2023
Institute of Earth Sciences, China University of Geosciences (Beijing), Beijing, 100083, China.
The water environment of large reservoirs is fragility due to effects from hydrological regulation of damming and anthropogenic inputs. As a critical path to quantify the natural chemical weathering and assess environmental risks, solute chemistry of river has been widely focused on. However, the complexed hydrological conditions of large reservoir affect the chemical compositions, and the significance of solute vertical geochemistry as an indicator of chemical weathering and water quality health remains explore.
View Article and Find Full Text PDFEnviron Res
November 2023
School of Civil Engineering, Southeast University, Nanjing 211189, China; Southeast University-Monash University Joint Research Centre for Future Cities, Nanjing 211189, China. Electronic address:
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