Driving factors for the changing epidemiology of vector-borne diseases - a review

Vector-borne diseases regularly occurred in moderate climate areas of Europe in past decades. The changing epidemiology of vector-borne diseases in Europe is caused by changes of environmental factors - amongst these climate change-and human activity (transport mobility, urbanisation, renaturation etc.). The occurrence of invasive vector species (for example the Asian tiger mosquito [Aedes albopictus] and the Asian bush mosquito [Aedes japonicus japonicus]) in new habitats pose a risk of pathogen transmission in naive host populations. On the other hand, the presence of native competent vectors and adequate habitats are sufficient for the effective spread of a pathogen as seen in the Bluetongue Virus epidemic in Europe in 2006 onwards or the spread of West Nile Virus (WNV) lineage 1 in USA in 1999. The vector-borne diseases posing threat of spread are very often of viral origin (WNV fever, Chikungunya fever, Dengue fever, Tick-borne encephalitis, Yellow fever, Japanese encephalitis), but there is also the potential for parasitic (Malaria, Dirofilariosis, Piroplasmosis and Leishmaniosis) or bacterial diseases (Tularaemia, Rickettsiosis). Recently, the fast spreading epidemic of mosquito-borne Zika virus infection implicated the need of preparedness and constant monitoring of vector-borne diseases and their vectors in order to provide fast answers to emerging disease control and prevention. In this paper, we review major driving factors for the changing epidemiology of selected vector borne diseases, provide a risk assessment for the introduction of new emerging diseases to Europe and present a new concept to face future challenges.