Environmental and spatial risk factors for the larval habitats of Plasmodium knowlesi vectors in Sabah, Malaysian Borneo

Byrne, I., Aure, W., Manin, B. O., Vythilingam, I., Ferguson, H. M. , Drakeley, C. J., Chua, T. H. and Fornace, K. M. (2021) Environmental and spatial risk factors for the larval habitats of Plasmodium knowlesi vectors in Sabah, Malaysian Borneo. Scientific Reports, 11, 11810. (doi: 10.1038/s41598-021-90893-1) (PMID:34083582) (PMCID:PMC8175559)

Abstract

Land-use changes, such as deforestation and agriculture, can influence mosquito vector populations and malaria transmission. These land-use changes have been linked to increased incidence in human cases of the zoonotic malaria Plasmodium knowlesi in Sabah, Malaysian Borneo. This study investigates whether these associations are partially driven by fine-scale land-use changes creating more favourable aquatic breeding habitats for P. knowlesi anopheline vectors. Using aerial remote sensing data, we developed a sampling frame representative of all land use types within a major focus of P. knowlesi transmission. From 2015 to 2016 monthly longitudinal surveys of larval habitats were collected in randomly selected areas stratified by land use type. Additional remote sensing data on environmental variables, land cover and landscape configuration were assembled for the study site. Risk factor analyses were performed over multiple spatial scales to determine associations between environmental and spatial variables and anopheline larval presence. Habitat fragmentation (300 m), aspect (350 m), distance to rubber plantations (100 m) and Culex larval presence were identified as risk factors for Anopheles breeding. Additionally, models were fit to determine the presence of potential larval habitats within the areas surveyed and used to generate a time-series of monthly predictive maps. These results indicate that land-use change and topography influence the suitability of larval habitats, and may partially explain the link between P. knowlesi incidence and deforestation. The predictive maps, and identification of the spatial scales at which risk factors are most influential may aid spatio-temporally targeted vector control interventions.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Fornace, Dr Kimberly and Ferguson, Professor Heather

Creator Roles

Ferguson, H. M.: Writing – review and editing

• Authors: Byrne, I., Aure, W., Manin, B. O., Vythilingam, I., Ferguson, H. M., Drakeley, C. J., Chua, T. H., and Fornace, K. M.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Scientific Reports
• Publisher: Nature Research
• ISSN: 2045-2322
• ISSN (Online): 2045-2322
• Copyright Holders: Copyright © 2021 The Authors
• First Published: First published in Scientific Reports 11: 11810
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
167761		Defining the biomedical, environmental and social risk factors for human infection with Plasmodium knowlesi	Heather Ferguson	Medical Research Council (MRC)	G1100796/1	Institute of Biodiversity, Animal Health and Comparative Medicine