Illinois saw its biggest one-day jump in coronavirus cases since the pandemic began, with 1,105 new cases confirmed on Sunday.
A total of 4,596 coronavirus cases have now been confirmed statewide in 47 counties.
In addition, 18 more deaths have been reported in connection to the virus, bringing the state's total number of coronavirus-related fatalities to 65.
11 of the 18 reported fatalities were in Cook County, according to IDPH. A man in his 60s died in DuPage County, while two men in their 90s passed away in Kane County after testing positive for the virus.
Kendall, LaSalle and St. Clair counties also reported coronavirus-related fatalities on Sunday.
With the newly confirmed cases, 47 of the state's 102 counties have now reported at least one confirmed case of the virus. Bond, Knox, Menard and Montgomery counties all reported their first confirmed cases of the virus on Sunday.
The announcement of new cases comes on the eighth day of the state's stay-at-home order, which remains in effect until April 7.
Earlier this week, Chicago Mayor Lori Lightfoot warned that the city could see upwards of 40,000 hospitalizations in the coming weeks and as U.S. health experts worry Cook County could become one of the nation's next hotspots.
"Forty thousand hospitalizations. Not 40,000 cases, but 40,000 people who require acute care in a hospital setting," Lightfoot said. "That number will break our healthcare system... This will push our city to the brink."