Poster, Junior Scientist Zoonoses Meeting, München/Oberschleißheim: 08.06.2015 - 10.06.2015
The geographical range of areas where dengue epidemics occur has expanded dramatically during the last decades. Up to now, dengue was generally considered an exclusively travel-related disease. However, first European cases of autochthonous dengue were reported in the Mediterranean; Madeira experienced an epidemic in 2012/2013. As arthropod vectors are ectothermic species, the environmental temperature directly determines the amplification of the virus inside the vector, i.e. the extrinsic incubation period (EIP), which is shortened at warmer temperatures If minimum temperature thresholds for the EIP are not exceeded, the virus cannot accomplish its amplification and the transmission to humans can be excluded. To identify European current and future areas at risk for dengue transmission, we combine the ecological knowledge on vector and virus with statistical species distribution models. First, we develop maps with areas at risk for a long-term establishment of the mosquito species Aedes albopictus, a well-known vector for dengue. Secondly, we detect areas where the temperature requirements of dengue EIP are fulfilled. In a final step, areas allowing possible transmission of dengue are detected by combining the results for vector and virus. Species distribution modelling was performed with R and the package biomod2, which allows the use of an ensemble of different modelling algorithms. All future maps are based on five different global climate models and the two representative concentration pathways RCP4.5 and RCP8.5 (IPCC AR5). The European distribution of Aedes albopictus is projected to increase up to the end of the century. However, the temperature-dependence of virus amplification limits areas of possible transmission. We illustrate that combining of projections for vector and pathogen as well as the inclusion of temperature dependent processes such as the virus amplification yields a more realistic estimation for possible future dengue transmission in Europe.