As of December 1, a total of 2,744 cases of WNV disease in humans had been reported from 596 counties in 42 states, 18.8% of the 3,142 U.S. counties. Among the cases, 1,165 (42.5%) were WNND (i.e., meningitis, encephalitis, or acute flaccid paralysis), 1,434 (52.2%) were West Nile fever (WNF), and 145 (5.3%) were unspecified illnesses. California reported 854 cases of WNV disease, 31% of the U.S. total, and 285 WNND cases, 25% of the U.S. total. Other focal outbreaks of WNND recurred throughout the United States, including in Illinois (133 cases), Texas (107), and Louisiana (100). In the New York City metropolitan area, WNV disease recurred for the seventh consecutive year. The highest incidence of WNND occurred primarily in the central United States, including South Dakota (4.8 WNND cases per 100,000 residents), Nebraska (2.1 cases per 100,000), and North Dakota (1.9 cases per 100,000). Nationally, reports of WNV disease began in late May, peaked during the third week in August, and lasted into November.