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Introduction: Dengue is a mosquito-borne viral infection that has become a major public health concern. About 390 million people are infected yearly. Increased global connectivity and population movement as well as climate change affect the global distribution of both dengue vectors and the virus, facilitating the spread of dengue to new geographic areas. Weather is an important factor determining mosquito behaviour and effectiveness of dengue virus transmission. Dengue epidemic potential depends on vectorial capacity of Aedes mosquitoes, which depend on climate, such as, temperature and diurnal temperature range. This study aims at identifying high-risk areas and high-risk time windows in Europe based on temperature, in order for timely vector surveillance and control.

Methods: Relative vectorial capacity (rVc) was used to estimate dengue epidemic potential. Using historical and projected temperature data over two centuries (1901–2099) and temperature dependent vector parameters for Aedes vectors, rVc was calculated for 10 selected European cities from Stockholm in the North to Malaga in the South.

Results: Compared to dengue endemic areas, rVc in Europe was lower and showed more prominent seasonality. The peak and width of the seasonal windows in rVc were generally higher in the South than the North. Currently, only South and Central-East Europe and the summer season corresponds to rVc that is over the threshold for possible dengue transmission. By the end of this century, in the best case scenario, all the Central and Southern European cities would be at risk for dengue transmission during the warmer months; in the worst case scenario, this risk would extend to Northern European to include Stockholm if dengue vectors were established and virus introduced.

Conclusion: As travel and globalization become more frequent channels for dengue vector and virus introduction, Europe may face the reality of more frequent dengue outbreaks in their warmer months. Madeira's outbreak in 2012 underlines this concern. The future's high risk area and time window depend sensitively on climate scenarios. Therefore, it is important to emphasize climate change mitigation and enhance vector surveillance and control in Europe.

Acknowledgement: This research was funded by the European Union 7th Framework Programme through 'DengueTools' (www.denguetools.net).

Disclosure: Nothing to disclose.