Arizona has most West Nile cases so far

Jun 17, 2004 (CIDRAP News) – Arizona has had 10 of the 14 human cases of West Nile virus (WNV) infection reported in the nation so far this year, the Centers for Disease Control and Prevention (CDC) said today.

As of Jun 15, one case each had been reported in California, New Mexico, South Dakota, and Wyoming, the CDC said in the Jun 18 issue of Morbidity and Mortality Weekly Report. The dates of illness onset ranged from May 8 to Jun 1; the case outcomes were not reported.

The agency said 12 blood donors with evidence of WNV infection have been reported, including 11 in Arizona and one in New Mexico. One of these donors later experienced neurologic disease from the virus, and two others had West Nile fever, according to the report.

Widespread screening of donated blood for WNV began in June 2003. At least 818 units of blood were removed from the blood supply last year because of contamination with the virus, but six cases of WNV infection were linked to blood transfusions, the CDC reported in April.

So far this year, 18 states have reported dead crows and other birds with WNV infection, and eight states have reported finding WNV-positive mosquitoes, the CDC said. Birds are the natural hosts of the virus, and mosquitoes spread it to humans.

See also:

CDC West Nile virus case count for 2004

CDC West Nile home page
http://www.cdc.gov/ncidod/dvbid/westnile/index.htm

Apr 8, 2004, CIDRAP News story "Six West Nile cases in 2003 linked to donated blood"