Abstract
BackgroundIn the past two decades the east African highlands have experienced several major malaria epidemics. Currently there is a renewed interest in exploring the possibility of anopheline larval control through environmental management or larvicide as an additional means of reducing malaria transmission in Africa. This study examined the landscape determinants of anopheline mosquito larval habitats and usefulness of remote sensing in identifying these habitats in western Kenya highlands.MethodsPanchromatic aerial photos, Ikonos and Landsat Thematic Mapper 7 satellite images were acquired for a study area in Kakamega, western Kenya. Supervised classification of land-use and land-cover and visual identification of aquatic habitats were conducted. Ground survey of all aquatic habitats was conducted in the dry and rainy seasons in 2003. All habitats positive for anopheline larvae were identified. The retrieved data from the remote sensors were compared to the ground results on aquatic habitats and land-use. The probability of finding aquatic habitats and habitats with Anopheles larvae were modelled based on the digital elevation model and land-use types.ResultsThe misclassification rate of land-cover types was 10.8% based on Ikonos imagery, 22.6% for panchromatic aerial photos and 39.2% for Landsat TM 7 imagery. The Ikonos image identified 40.6% of aquatic habitats, aerial photos identified 10.6%, and Landsate TM 7 image identified 0%. Computer models based on topographic features and land-cover information obtained from the Ikonos image yielded a misclassification rate of 20.3–22.7% for aquatic habitats, and 18.1–25.1% for anopheline-positive larval habitats.ConclusionOne-metre spatial resolution Ikonos images combined with computer modelling based on topographic land-cover features are useful tools for identification of anopheline larval habitats, and they can be used to assist to malaria vector control in western Kenya highlands.
Highlights
IntroductionIntroduction to remote sensingLondon, The Guildford Press; 1996:618.51. Quinn P, Beven K, Chevallier P, Planchon O: The prediction of hillslope flow paths for distributed hydrological modeling using digital terrain models
Introduction to remote sensingLondon, The Guildford Press; 1996:618.51
The objective of this study was to assess the potential of aerial photos, Landsat Thematic Mapper (TM) 7 and Ikonos images for identifying larval habitats of malaria vectors and for determining other topographic features associated with anopheline larval habitats in western Kenya highlands where frequent malaria outbreaks have been reported [42,43,44,45,46]
Summary
Introduction to remote sensingLondon, The Guildford Press; 1996:618.51. Quinn P, Beven K, Chevallier P, Planchon O: The prediction of hillslope flow paths for distributed hydrological modeling using digital terrain models. Terrain Analysis Using Digital Elevation Models (TauDEM) [ http://www.engineering.usu.edu/dtarb/] 53. There is a renewed interest in exploring the possibility of anopheline larval control through environmental management or larvicide as an additional means of reducing malaria transmission in Africa. Current strategies for malaria control involve treating infected individuals with anti-malarial drugs to clear the parasites, and reducing humanmosquito contact rates through vector control efforts. Anti-malarial drugs have little impact on the intensity of transmission at the community level because most drugs do not reduce the production of Plasmodium gametocytes, the parasite stage responsible for initiation of infection in mosquitoes [2]. Recent large field trials in Kenya demonstrated that insecticide-treated bed nets (ITN) can prevent 1 in 4 infant deaths in areas of intense perennial malaria transmission, if bed nets are used properly and re-treated with insecticide at appropriate intervals [3,4]. Coverage and compliance are limited and emergence of insecticide-resistance genes has hindered the effectiveness of ITN programmes [5,6,7,8]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
