Severe West Nile Virus outbreaks following climate changes in northern Italy. Need of strict surveillance and patient long term follow-up.

Recent climate change with the consequent rise of the earth temperature, have changed the migration routes of some species of birds, potential reservoir of Arboviruses, coming from Africa and the Middle East. In European countries with temperate climates, this phenomenon has led to the emergence of West Nile Virus (WNV) outbreaks, favored by the presence of competent vectors (Culex mosquitoes) in the mentioned territories. In some Italian regions such us Emilia Romagna and Veneto, virus circulation has become endemic in the months between June and November. We present 18 cases of West Nile Neuroinvasive Disease (WNND) admitted to the Infectious Diseases Wards of Ferrara and Rovigo between 2008 and 2013 (August), presenting meningo-encephalitis (group 1, 9 patients) and mengingo-encephalitis with acute flaccid paralysis (group 2, 9 patients). Of the 18 patients, 13 were men (72%) and 5 women (28%); median age 71 (range 42-84). Of these cases, only one was imported (Romania). All, but one, had risk factors for WNND. In an average follow-up of 36 months (12-60) occurred 9 deaths, 4 (21%) during the hospital stay, 5 (28%) after discharge (range 7 days-12 months), with a rate lethality of 50%. The age (> 64) was the only factor significantly related to mortality (p < 0.02). Functional or cognitive deficits, from mild to severe, have been reported in all patients. WNND is a disease with high mortality, burdened by development of neurological sequelae, more pronounced and debilitating in patients with acute flaccid paralysis, which showed no recovery of physical function and loss of self-sufficiency, in the long term. It is a serious and debilitating illness, whose potential transmission should be prevented through multidisciplinary (entomological and veterinary) territorial strict surveillance and activation systems of "early detection" through screening on blood transfusions and transplant organs