Background: The impact of weather and climate on malaria transmission has attracted considerable attention in recent years, yet uncertainties around future disease trends under climate change remain. Mathematical models provide powerful tools for addressing such questions and understanding the implications for interventions and eradication strategies, but these require realistic modeling of the vector population dynamics and its response to environmental variables. Methods. Published and unpublished field and experimental data are used to develop new formulations for modeling the relationships between key aspects of vector ecology and environmental variables. These relationships are integrated within a validated deterministic model of Anopheles gambiae s.s. population dynamics to provide a valuable tool for understanding vector response to biotic and abiotic variables. Results: A novel, parsimonious framework for assessing the effects of rainfall, cloudiness, wind speed, desiccation, temperature, relative humidity and density-dependence on vector abundance is developed, allowing ease of construction, analysis, and integration into malaria transmission models. Model validation shows good agreement with longitudinal vector abundance data from Tanzania, suggesting that recent malaria reductions in certain areas of Africa could be due to changing environmental conditions affecting vector populations. Conclusions: Mathematical models provide a powerful, explanatory means of understanding the role of environmental variables on mosquito populations and hence for predicting future malaria transmission under global change. The framework developed provides a valuable advance in this respect, but also highlights key research gaps that need to be resolved if we are to better understand future malaria risk in vulnerable communities.
Bibliographical noteFunding Information:
The authors would like to thank Henri Tsila for providing unpublished data that formed the basis of Figure 4. PEP and EM would like to thank the Grantham Institute of Climate Change at Imperial College London for funding this research. EM also acknowledges the Eck Institute for Global Health at the University of Notre Dame for part funding this work. None of the funding bodies mentioned contributed to the design, collection, analysis or interpretation of data, nor the writing of the manuscript or decision to submit. The authors would like to thank the two anonymous reviewers whose comments greatly improved this manuscript.
- Anopheles gambiae s.s.
- Climate change
- Mathematical modeling