West Nile virus activity--United States, January 1-August 15, 2006.

This report summarizes West Nile virus (WNV) surveillance data reported to CDC through ArboNET as of 3 a.m. Mountain Daylight Time, August 15, 2006. A total of 26 states had reported 388 cases of human WNV illness to CDC. A total of 214 (56%) cases for which such data were available occurred in males; median age of patients was 49 years (range: 2-91 years). Dates of illness onset ranged from January 6 to August 10; a total of 13 cases were fatal. A total of 68 presumptive West Nile viremic blood donors (PVDs) have been reported to ArboNET during 2006. Of these, 20 were reported from Nebraska; 18 were reported from Texas; five were reported from California; four were reported from Utah; three each were reported from Oklahoma and South Dakota; two each were reported from Idaho, Iowa, Kentucky, and Mississippi; and one each was reported from Arizona, Colorado, Minnesota, Nevada, North Dakota, Wisconsin, and Wyoming. Of the 68 PVDs, 10 persons (median age: 43 years [range: 18-59 years]) subsequently had West Nile fever.