Poster, Joint Conference - German Symposium on Zoonoses Research and 7th International Conference on Emerging Zoonoses, Berlin: 2014-10-16 - 2014-10-17
Current developments in the spread of arthropods as well as pathogens in Europe emphasize the importance and urgency of well-informed projections concerning the expectable future development. The basic idea behind the identification of current and future areas at risk of zoonoses is the combination of ecological knowledge covering the pathogen and the vector; and where possible the host. Within a pilot project of the German Research Platform for Zoonoses (‘Zoonosis RISKTOOL’) we aim to develop current and future risk maps for Dengue and West Nile with special focus on the cold tolerance of the vector and the extrinsic incubation period (EIP) of the pathogen. Based on these examples we further develop a Zoonosis RISKTOOL allowing a general application of the approach for other zoonoses. Modelling is performed with the open-source statistic software R and the implemented package biomod2. Biomod2 allows the use of an ensemble of different modelling algorithms and hence a reduction of the uncertainty by using only one algorithm. The RISKTOOL provides all necessary steps: variable selection, model calibration and validation, implementation of ecological knowledge as well as current and future projections of the distribution of zoonoses. As study vectors we used Aedes albopictus and Aedes japonicus. The cold tolerance of both vectors was tested experimentally. For Dengue we further estimated the EIP for different temperature values from the literature. Both ecological aspects act as a filter for the distribution models, i.e. we acknowledge ecological constraints. The EIP is displayed as a temperature-duration relationship, which means that with an increase in temperature the duration of the EIP becomes shorter and hence the risk for a pathogen transmission increases. The experiment on the cold tolerance revealed that the combination of the minimum temperature and the duration of the exposure is the most important variable constraining the reproduction and hence the long-term establishment of the vector. Assessing the risk of a spread of zoonoses requires the combination of projections for vector and pathogen as well as the inclusion of ecological constraints to yield a more realistic estimation. Prospectively, the integration of the host, especially for further zoonoses, will be necessary.