The state has reported 1,038 confirmed cases and another 823 suspected cases, bringing the total to 6,849.
Michigan has reported 717 cases and 3,974 confirmed cases.
In Illinois, the state reported 691 cases and 5,734 confirmed cases, a total of 5,566.
In the northern half of the state, the outbreak has been concentrated in the Chicago metro area.
The state reported an average of 767 cases per day through Thursday, compared to a statewide average of 1,079.
In Chicago, the number of confirmed cases was up by 4.8 percent, the city reported Thursday.
The number of suspected cases was unchanged at 1,084.
In Michigan, the majority of the cases are in Detroit.
In the northern part of the metro area, the countywide average was 1,036, compared with an average statewide of 1:59.