Sep 29, 2005 (CIDRAP News) Forty states have reported a total of 1,804 cases of West Nile virus (WNV) infection, including 52 deaths, so far this year, numbers about even with last year's pace, the Centers for Disease Control and Prevention (CDC) said today.
At this time last year, 1,784 WNV cases, including 56 deaths, had been reported, the CDC reported in Morbidity and Mortality Weekly Report.
The record year for West Nile in the United States was 2003, with more than 9,800 cases, of which 4,827 had been reported by mid-September.
This year's cases include 696 involving neurologic disease (encephalitis, meningitis, or myelitis), 993 with fever but no neurologic disease, and 115 unspecified cases, the CDC reported.
California has had by far the most cases with 681, followed by South Dakota, 208; Illinois, 172; Louisiana, 81; and Colorado, 75. No cases have been reported in Alaska, Hawaii, Washington, Virginia, West Virginia, Maine, New Hampshire, Vermont, New Jersey, or Delaware, according to the CDC.
Evidence of WNV has been found in blood from 321 blood donors so far this year, the report says. Seventy-four of those donors subsequently had West Nile fever or, in three cases, neuroinvasive disease. Blood banks began screening blood for WNV in 2003, after 23 West Nile cases were linked with donated blood in 2002.
CDC. Update: West Nile virus activityUnited States, 2005. MMWR 2005 Sep 30;54(38):964-5 [Full text]