Clinical Presentation

West Nile Virus

In North America West Nile Virus (WNV), a mosquito-borne flavivirus infection, was first identified in the fall of 1999 in a relatively localized outbreak in New York City and neighboring counties. Since then the virus has spread dramatically across the entire continental United States and, in 2002, more than 2,000 cases of WNV human neuroinvasive disease were reported in 44 of the 48 continental states.

Overview 

West Nile virus is a disease transmitted to humans and animals through the bite of an infected mosquito. Mosquitoes become infected after feeding on infected birds.

West Nile virus is common in birds, humans and other animals in Africa, Australia, Eastern Europe, west Asia and the Middle East.

It was first detected in North America in 1999, and has since spread across the continental United States and Canada.