Epidemiological surveillance of West Nile neuroinvasive diseases in Italy, 2008 to 2011.

ABSTRACT

We describe the geographical and temporal distribution of West Nile neuroinvasive diseases (WNND) cases in Italy from 2008 to 2011. The increasing number of confirmed human cases from eight in 2008 to 18 in 2009 and the occurrence of the virus in a larger geographical area in 2009 (moving from east to west) prompted the Ministry of Health to publish, in spring 2010, a national programme for WNND human surveillance, comprising veterinary and vector surveillance. Subsequently, in 2011, a new national plan on integrated human surveillance of imported and autochthonous vector-borne diseases (chikungunya, dengue and West Nile disease) was issued. Between 2008 and 2011, 43 cases of WNND were reported from five regions in Italy with a case fatality rate of 16%. The incidence of WNND during the entire study period was 0.55 per 100,000 population (range 0.06­0.23 per 100,000). During 2011, two new regions (Friuli-Venezia Giulia and Sardinia) reported confirmed cases in humans. Integrated human, entomological and animal surveillance for West Nile virus is a public health priority in Italy and will be maintained during 2012.