The Kane County woman fell ill in early August and was later diagnosed with West Nile fever. She did not require hospitalization, said Dr. Eric Whitaker, state public health director.
There has been one West Nile fatality in Illinois this year. A 58-year-old DuPage County man who was hospitlaized after developing encephalitis died Sept. 1
Illinois was the nation's West Nile hotspot in 2002 with 884 cases and 66 deaths. There were 54 confirmed human cases in 2003, including one death.
Public health officials expect mosquito-borne West Nile disease to peak in September and remind people to take simple precautions while enjoying the last weeks of outdoors summer activity.
People over 50 have the highest risk of severe disease.