Linking a compartment model for West Nile virus with a flight simulator for vector mosquitoes

Abstract

Compartmental SIR and SEIR models have become the state of the art tools to study infection cycles of arthropod-borne viruses such as West Nile virus in specific areas. In 2018, the virus was detected for the first time in Germany, and incidents have been reported in humans, birds, and horses.

The aim of the work presented here was to provide a tool for estimating West Nile virus infection scenarios, local hotspots and dispersal routes following its introduction into new locations through the movements of mosquitoes. For this purpose, we adapted a SEIR model for West Nile virus to the conditions in Germany (temperatures, geographical latitude, bird and mosquito species densities) and the characteristic transmission and life trait parameter of a possible host bird and vector mosquito species. We further extended it by a spatial component: an agent-based flight simulator for vector mosquitoes. It demonstrates how the female mosquitoes move within the landscape due to habitat structures and wind conditions and about how many of them leave the region in the different cardinal directions.

We applied the space–time coupled model with a daily temporal and spatial resolution of 100 m x 100 m to the Eurasian magpie (Pica pica) and the Asian bush mosquito (Aedes japonicus japonicus). Both species are widely distributed in Germany and discussed as important hosts and vectors, respectively. We also applied the model to three study regions in Germany, each representing slightly different climatic conditions and containing significantly different pattern of suitable habitats for the mosquito species.