The first continental population dynamics model of the Asian tiger mosquito driven by climate and environment

The Asian tiger mosquito, Aedes albopictus, is an invasive vector species. It is capable of transmitting more than 20 arboviruses, and is responsible for chikungunya, dengue, and zika transmission. Urbanisation, globalisation, and climate change are expected to expand its habitable range and increase the global vector-borne disease burden in the coming decades. To plan effective control strategies, early-warning and decision support systems are urgently needed.

We developed a climate- and environment-driven population dynamics model of Aedes albopictus with extensive geospatial applicability. The foundation of the model is the age- and stage-structured population dynamics model of Erguler et al. (2016)¹. We replaced its rainfall- and human population density-dependent breeding site component with a large-scale mechanistic ecological model. The extension effectively created an ecological-dynamic model hybrid capable of representing niche dependence and response to changing environmental and meteorological conditions over time and under various land characteristics. To the best of our knowledge, this is the first spatiotemporal mechanistic model developed with a capacity to learn from both vector presence and longitudinal abundance data.

We calibrated the model with an extensive field surveillance dataset by combining the data collected through the AIMSurv project, the first pan-European harmonized surveillance of Aedes invasive mosquito species of relevance for human vector-borne diseases, and the global surveillance records available from VectorBase MapVEu. By deriving the model structure and environmental dependencies from the literature and allowing a complete re-configuration of the entire parameter set, we asserted the biological relevance and geospatial applicability, which extends over Europe and North America.

We corroborate that temperate northern territories are becoming increasingly suitable for Aedes albopictus establishment, while neighbouring southern territories become less suitable, as climate continues to change. We identify potential hotspots over Europe and North America by employing the combination of vector abundance and activity as a proxy to pathogen transmission risk.  By investigating routes of introduction to new territories, we demonstrate the significant role of dynamic environmental suitability in the highly efficient spread of this invasive mosquito.

The model is scheduled for integration into the "Climate-driven vector-borne disease risk assessment platform", to predict habitat suitability and dynamic abundance of important disease vectors and the risk of diseases transmitted by them at any location and time up to the end of the century. With the continental model of Aedes albopictus, the platform will reliably inform public health professionals and policy makers and contribute to the global strategies of integrated vector management.

¹ Erguler K, Smith-Unna SE, Waldock J, Proestos Y, Christophides GK, Lelieveld J, Parham PE. Large-scale modelling of the environmentally-driven population dynamics of temperate Aedes albopictus (Skuse). PloS one. 2016 Feb 12;11(2):e0149282.