The latest cases of the mosquito-borne virus were a 74-year-old Chicago woman hospitalized for West Nile encephalitis, a swelling of the brain, in mid-August and a 53-year-old suburban man diagnosed with West Nile fever in early August.
There have been 34 cases of West Nile disease in Illinois this year, including the death of a 58-year-old man Sept. 1.
Illinois led the nation with 884 confirmed West Nile cases in 2002, including 66 deaths, but the number of infections dropped to 54 cases in 2003 with one death.
People over 50 have the highest risk of severe disease. The infection rate peaks in August and September, said Dr. Eric Whitaker, state public health director.