WASHINGTON - Isolated, but more severe cases of West Nile have occurred this year and doctors believe the virus may be mutating.
Recent cases have affected younger, healthier patients, and have resulted in more serious brain damage.
The ways in which the virus is attacking in 2012 has led doctors in Texas, Michigan and Mississippi to believe that it may be mutating, according to The Washington Post.
Some patients with recent cases are experiencing an inability to talk, write and paralysis on one side of the body similar to a stroke. Previous severe cases more typically occurred in the elderly or in people with suppressed immune symptoms.
The Centers for Disease Control and Prevention told The Washington Post that because there are so many more cases this year, it's reasonable some would be more severe and that there would be a wider variety of symptoms.
WTOP's Kristi King contributed to this report.
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