Vortrag, Continents under Climate Change - Conference on the Occasion of the 200th Anniversary of the Humboldt-Universität zu Berlin, Berlin: 21.04.2010 - 23.04.2010
Activity phase, establishment and survival of cold-blooded disease vectors are strongly connected with climatic conditions. Therefore climate change is expected to be accompanied with the spatial expansion of vector-borne diseases to higher latitudes and altitudes, some of them being of tropical or subtropical origin. Here, this emerging biorisk is highlighted for Europe. We investigate the example of native insect vectors as well as non-native but highly invasive vectors in combination with the possibly transmitted diseases by these vectors. The infectious disease Leishmaniasis is endemic in Southern Europe. This is also true for the specific vectors, phlebotomine sandflies. Recent sandfly catches and autochthonous cases of visceral leishmaniasis in humans and their domestic animals in Central Europe hint on northwards spread. Until now, most cases of Leishmaniasis at higher latitudes are reported for travellers or refer to imported Mediterranean dogs. Knowledge about future habitat suitability for sandfly vectors in Europe is scarce. Therefore, climatic requirements are detected and bioclimatic envelopes are modelled. These envelopes can be connected to future climatic conditions by combining them with geographically explicit regional climate change simulations. Beyond climatic drivers, the interplay with globalisation may also support the spread of disease vectors in Europe. High invasive capacity in combination with the global shipping transport of freights made the Asian tiger mosquito (Aedes albopictus) - originally native in South-East Asia - a “global player”. This potential vector of various infectious diseases (e.g. Chikungunya, Dengue and West-Nile) is listed as one of the 100 “Worlds Worst Invaders”. In 2007 Aedes caused a Chikungunya-epidemic in Northern Italy. Therefore, especially Switzerland and France combat this mosquito to avoid its establishment and further spread. Conceivably, climate change may provide suitable conditions in European cities with large seaports at higher latitudes (e.g. Rotterdam or Hamburg), wherefrom the imported Asian tiger mosquito then could conquer other areas in Central Europe. Nevertheless, vector establishment is not necessarily equivalent with disease outbreak. For this purpose, additional factors like the abundance of reservoir hosts and pathogen requirements (e.g. thermal constraints) must be fulfilled. As a matter of fact, European health care is challenged by novel threats and must be prepared. This calls for interdisciplinary research and close connections between policy and science in order to become proactive or if necessary to adapt surveillance systems in time.