Geospatial modelling of dry season habitats of the malaria vector, Anopheles funestus, in south-eastern Tanzania

Kahamba, N. F., Okumu, F. O. , Jumanne, M., Kifungo, K., Odero, J., Baldini, F. , Ferguson, H. and Nelli, L. (2024) Geospatial modelling of dry season habitats of the malaria vector, Anopheles funestus, in south-eastern Tanzania. Parasites and Vectors, 17, 38. (doi: 10.1186/s13071-024-06119-6)

[img] Text
317606.pdf - Published Version
Available under License Creative Commons Attribution.



Background Anopheles funestus is a major malaria vector in Eastern and Southern Africa and is currently the dominant malaria-transmitting vector in many parts of Tanzania. Previous research has identified its preference for specific aquatic habitats, especially those that persist in dry months. This observation suggests the potential for targeted control through precise habitat mapping and characterization. In this study, we investigated the influence of habitat characteristics, land cover and human population densities on An. funestus distribution during dry seasons. Based on the results, we developed a habitat suitability model for this vector species in south-eastern Tanzania. Methods Eighteen villages in south-eastern Tanzania were surveyed during the dry season from September-December 2021. Water bodies were systematically inspected for mosquito larvae and characterized by their physico-chemical characteristics and surrounding environmental features. A generalized linear model was used to assess the presence of An. funestus larvae as a function of the physico-chemical characteristics, land use and human population densities. The results obtained from this model were used to generate spatially explicit predictions of habitat suitability in the study districts. Results Of the 1466 aquatic habitats surveyed, 440 were positive for An. funestus, with river streams having the highest positivity (74%; n = 322) followed by ground pools (15%; n = 67). The final model had an 83% accuracy in predicting positive An. funestus habitats, with the most important characteristics being permanent waters, clear waters with or without vegetation or movement and shading over the habitats. There was also a positive association of An. funestus presence with forested areas and a negative association with built-up areas. Human population densities had no influence on An. funestus distribution. Conclusions The results of this study underscore the crucial role of both the specific habitat characteristics and key environmental factors, notably land cover, in the distribution of An. funestus. In this study area, An. funestus predominantly inhabits river streams and ground pools, with a preference for clear, perennial waters with shading. The strong positive association with more pristine environments with tree covers and the negative association with built-up areas underscore the importance of ecological transitions in vector distribution and malaria transmission risk. Such spatially explicit predictions could enable more precise interventions, particularly larval source management, to accelerate malaria control.

Item Type:Articles
Additional Information:This work was supported in whole by the Bill & Melinda Gates Foundation (Grant No. INV-002138 to Ifakara Health Institute).
Glasgow Author(s) Enlighten ID:Okumu, Professor Fredros and Kahamba, Najat Feruzi and Baldini, Dr Francesco and Ferguson, Professor Heather and Nelli, Dr Luca and Odero, Mr Joel
Authors: Kahamba, N. F., Okumu, F. O., Jumanne, M., Kifungo, K., Odero, J., Baldini, F., Ferguson, H., and Nelli, L.
College/School:College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
College of Medical Veterinary and Life Sciences
College of Medical Veterinary and Life Sciences > School of Infection & Immunity
Journal Name:Parasites and Vectors
Publisher:BioMed Central
ISSN (Online):1756-3305
Copyright Holders:Copyright: © The Author(s) 2024
First Published:First published in Parasites and Vectors 17: 38
Publisher Policy:Reproduced under a Creative Commons licence

University Staff: Request a correction | Enlighten Editors: Update this record

Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
309514Population biology and genomic studies of Anopheles funestus in TanzaniaHeather FergusonBill and Melinda Gates Foundation (GATES)INV-002138Institute of Biodiversity, Animal Health and Comparative Medicine