7/2/2010

The CDC on Thursday reported that there were 386 West Nile virus cases and 33 deaths in the U.S. last year. The numbers were an improvement compared with the 3,000 cases and more than 260 deaths for 2002 and 2003. Only one serious case has been seen so far this year. The reduced number of cases could be attributed to the development of immunity to the virus in birds.

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