Provisional surveillance summary of the West Nile virus epidemic--United States, January-November 2002.

This report presents provisional summary surveillance data about West Nile virus (WNV) activity that were reported to CDC during January 1-November 30, 2002, through the ArboNET surveillance network. In 2002, the reported numbers of human and animal infections increased, and the geographic range of WNV activity expanded substantially. These data underscore the need for intensive surveillance to detect and quantify WNV activity in areas where humans are at risk, public education to teach persons how to prevent mosquito bites, and sustained and integrated mosquito-control activities.