West Nile virus activity--United States, June 30-July 6, 2004.

During June 30-July 6, a total of 21 human cases of West Nile virus (WNV) illness were reported from two states (Arizona and California). During 2004, eight states have reported a total of 78 human cases of WNV illness to CDC through ArboNET. Of these, 57 (73%) were reported from Arizona. Forty-seven (61%) of the 78 cases occurred in males; the median age of patients was 53 years (range: 1-84 years); the dates of illness onset ranged from April 23 to June 28; and one case was fatal.