West Nile fever

West Nile virus (WNV) is a mosquito-borne zoonotic arbovirus belonging to the genus Flavivirus in the family Flaviviridae. It is found in temperate and tropical regions of the world. It was first identified in the West Nile subregion in the East African nation of Uganda in 1937. Prior to the mid-1990s, WNV disease occurred only sporadically and was considered a minor risk for humans, until an outbreak in Algeria in 1994, with cases of WNV-caused encephalitis, and the first large outbreak in Romania in 1996, with a high number of cases with neuroinvasive disease. WNV has now spread globally, with the first case in the Western Hemisphere being identified in New York City in 1999; over the next five years, the virus spread across the continental United States, north into Canada, and southward into the Caribbean islands and Latin America. WNV also spread to Europe, beyond the Mediterranean Basin, and a new strain of the virus was identified in Italy in 2012. WNV spreads on an ongoing basis in Africa, Asia, Australia, the Middle East, Europe, Canada and in the United States. In 2012 the US experienced one of its worst epidemics in which 286 people died, with the state of Texas being hard hit by this virus.