State records highest single-day total of new COVID-19 cases: 4,015
Illinois set a single-day record Thursday when 4,015 new cases of COVID-19 were reported by state health officials.
At least two suburban counties also set bleak one-day new-case records.
Health officials reported 53 more people have died from the respiratory disease, bringing the state's death toll to 9,127 since the outbreak began.
The new caseload announced Thursday was the most since May 12, when 4,014 new cases were reported. The state reported 5,368 new cases on one day in early September, but that was after computer issues were remedied, allowing the Illinois Department of Public Health to finally record several days' worth of cases.
As of Thursday, 331,620 Illinois residents have contracted COVID-19 since the start of the pandemic, state health records show.
Thursday's new cases, in combination with 67,086 more test results, brings the state's infection rate to 4.9%, based on a seven-day rolling average.
Thursday also marked the start of the state including antigen test results in its daily records. These "rapid-result" tests can provide results in less than an hour. But the FDA notes on its website that antigen tests are "more likely to miss an active coronavirus infection compared to molecular tests."
Previously, only molecular COVID-19 tests were being recorded by IDPH since so few antigen tests were available - less than 1% of the total tests performed, state officials said. Antigen tests have become more widely available in recent days.
But only 1,112 of Thursday's test results were antigen tests, according to figures found on the IDPH COVID-19 statistics website, dph.illinois.gov/covid19. That's less than 2% of all of Thursday's test results.
Nearly 40% of the new cases announced Thursday involved suburban residents, according to IDPH figures. Suburban Cook County and the five collar counties of DuPage, Kane, Lake, McHenry and Will accounted for 1,571 of the new cases. Chicago accounted for 18% of the new cases, while the remaining 42% of the cases were diagnosed in downstate residents.
Suburban Cook County also recorded the most new cases in one day Thursday, with 753 residents being diagnosed with the virus. The same went for Lake County, where 226 new cases were diagnosed.
DuPage County saw 200 new infections, only the second time the one-day total there has reached that high.
Kane County, which recorded 144 cases Thursday, saw it's seven-day average infection rate climb to 7.9%, the highest in the suburbs.
Thursday also saw the first time the state has recorded two straight days of 40 or more deaths from the virus since June 19 and June 20. The state is averaging 31 COVID-19 deaths a day for the past week. Two months ago, the state was averaging just 14 deaths a day from the virus.
Hospitalizations declined slightly Wednesday night, with 1,932 patients being treated for the virus statewide, according to IDPH figures. Of those hospitalized, 388 were being treated in intensive care and 147 of those patients are on ventilators.