Albieri A, R Bellini, M Calzolari, P Bonilauri, M Chiari, D Lelli, M Tamba, M Dottori, G Capelli, S Ravagnani, P Mulatti, C Casalone, A Pautasso, C Radaelli
20th ESOVE Conference,
2-7 October 2016 – Lisbon, Portugal.
West Nile Virus (WNV) is an emerging threat in Europe, with more than 1000 human cases reported since 2010 in the European Union. In Italy, after the first detection in 1998 in Padule di Fucecchio (Tuscany), WNV reappeared northward in Pianura Padana in 2008-2009 affecting Emilia-Romagna, Veneto, Lombardia regions where human cases were recorded. The virus was continuously detected in subsequent years, with different strains circulating over the years and in different areas of the Pianura Padana.
The environmental surveillance, particularly based on entomological and bird sampling, is performing well in the early detection of virus circulation, usually before the appearance of human and equine cases. From 2013 five neighboring Regions of Northern Italy activated a similar entomological surveillance, allowing the monitoring of the whole Pianura Padana territory (about 46.000 Km2). We compared WNV circulation maps of Pianura Padana from 2013 to 2015 using spatial analysis techniques (Kernel Density Estimation, Directional distribution, Mean center evaluation) in order to determine the spatial evolution of the phenomenon. From 2013 to 2015 we observed an expansion of the WNV circulation area (the KDE west forehead move of around 82 km in 2014 respect to 2013 and of around 56 km in 2015 respect to 2014) and the mean center moved toward west of around 76 km from 2013 to 2015.