Exotic vector and pathogen surveillance programme in Belgium

Several vector-borne diseases (e.g. theileriosis, babesiosis, bluetongue virus (BTV), Schmallenberg virus (SBV), West-Nile virus (WNV)) are emerging in Belgium or in other European countries and some are now endemic. The increase in international transport, the removal of quarantine measures within the EU zone and the growing tourism are responsible for the increasing risk of spread of pathogens and vectors. Climate change also exerts a significant influence on the survival and spread of arthropod vectors as well as on the vectorial capacity and competence of these exotic, but also of endemic arthropods. Strengthening surveillance of exotic vectors (mosquitoes, biting midges (Culicoides) and ticks) and their pathogens in areas at risk of importation or spread and risk of pathogen transmission is therefore required. For Belgium, the following exotic vectors or vector-borne pathogens pose a risk: the Asian tiger mosquito (Aedes albopictus), the Asian rock pool mosquito (Aedes japonicus japonicus), Aedes koreicus, the ornate dog tick Dermacentor reticulatus and, BTV, SBV, equine Babesiosis and Theileriosis.
Following the implementation of invasive mosquito surveillance in Belgium in 2012, to evaluate the guidelines of the European Centre for Disease Prevention and Control (ECDC 2012, Deblauwe et al. 2014a), the surveillance continued in 2013 including that of biting midges and ticks, and their most important pathogens. In 2014 and 2015 only invasive mosquitoes and exotic ticks (Dermacentor) were surveyed because of the necessity to intensify the surveillance measures for Ae. albopictus at two points of entry. In 2016 the focus was on Culicoides and invasive mosquitoes. As bluetongue (BTV8 since August 2015 and BTV4 since 2014) is emerging again in Europe, priority should be given to the monitoring of Culicoides. Furthermore, Ae. albopictus has become a yearly appearing threat in Belgium which also necessitated the surveillance of high-risk PoE of invasive mosquitoes in 2016.