It is the second-highest number of cases reported in a single day since the pandemic began, behind only the 17,608 cases reported on November 5, 2020.
There have been 2,002,360 total COVID cases, including 27,357 deaths in the state since the pandemic began.
The seven-day statewide test positivity rate is 7.9%.
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"Between delta, which was highly transmissible, and now omicron, which is maybe two or three times more transmissible, a lot of us are going to have, unfortunately, a date with omicron," said IDPH Commissioner Dr. Ngozi Ezike.
Within the past 24 hours, laboratories have reported testing 199,406 new specimens for a total of 42,986,170 since the pandemic began.
At testing sites across the city and suburbs, lines have stretched for blocks and waits even longer in the final days before Christmas.
"It's kind of hard because a lot of places don't do appointments. You just kind of have to press your luck and hopefully choose a time where it's not super busy," said Eve, who asked we only use her first name, as she waited.
As of Tuesday night, 4,178 patients in Illinois were reported to be in the hospital with COVID-19. Of those, 867 patients were in the ICU and 451 patients with COVID-19 were on ventilators.
Many hospitals are now faced with tough decisions.
"Absolutely, we know that some hospitals have already voluntarily-- it's not really voluntary, because of the severe bed crunch they have already started limiting non-emergent procedures," Ezike said.
Dr. Fauci speaks one-on-one with ABC7's Sarah Schulte
A total of 18,775,064 vaccine doses have been administered in Illinois as of Tuesday, and 60.09% of the state's population is fully vaccinated. The seven-day rolling average of vaccines administered daily is 66,113.