West Nile encephalitis (WNE) is an acute arboviral infection caused by a virus of the Flaviviridae family transmitted by an infected mosquito, that is asymptomatic in the majority of cases but that can present in rare occasions with mild flulike symptoms such as low-grade fever, arthralgia, myalgia, and/or rash, or with neurologic manifestations including meningitis, encephalitis with mental confusion or disorientation, tremors and acute flaccid paralysis/poliomyelitis.