COVID by the Numbers: All 102 Illinois Counties Experiencing ‘High Transmission' Rates of Coronavirus

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All 102 counties in the state of Illinois are currently experiencing “high transmission” levels of COVID-19, while many are also experiencing dramatic growth in other metrics designed to illustrate how rapidly the virus is spreading.

The Centers for Disease Control and Prevention considers a county to have a “high transmission” rate of COVID if 100 or more residents per 100,000 individuals have contracted the virus in a given week.

Currently, all 102 of Illinois’ counties have hit that threshold, according to the latest data from IDPH and the CDC, and no state is currently lower than 208 cases per 100,000 residents.

Piatt County, located just to the west of Champaign County, is reporting one of the state’s highest totals, with 881.06 cases per 100,000 residents in the last week. That is nearly nine times more than the CDC’s “high transmission” threshold, and the county’s positivity rate is also above 10%, according to IDPH data.

Iroquois County, located just to the south of Kankakee County, has reported 730.25 new cases of COVID per 100,000 residents in the last week.

The county has reported 33 total cases in the last seven days, averaging more than 400 new cases per 100,000 residents over that time.

According to the latest data from IDPH, at least one Illinois county has a positivity rate of greater than 20% with Hamilton County, located in the southern portion of the state, reporting a 20.11% positivity rate over the last week.

The CDC says that any county with a positivity rate of higher than 10% is considered to be at a “high transmission” level of virus spread.

Numerous other counties are above 15% positivity, including Pope, Henderson and Hancock counties.

In the NBC 5 viewing area, Grundy County has reported a positivity rate of 12.56% in the last week, while Kankakee County has reported a positivity rate of 11.44%.

Cook County has one of the lowest positivity rates in the state, currently sitting at 4.15% in the last week. The county has reported 14,878 new COVID cases in the last week, averaging 288.88 new cases per 100,000 residents. That mark is nearly three times higher than the “high transmission” threshold from the CDC, but is also one of the lowest rates in the state.  

Here are all the latest figures from the Illinois counties in the NBC 5 viewing area (data for all 102 counties can be found here):

Cook County –

Total Cases in Last Seven Days: 14,878

Cases Per 100K Residents: 288.88

Positivity Rate: 4.15%

DeKalb County –

Total Cases in Last Seven Days: 463

Cases Per 100K Residents: 441.39

Positivity Rate: 8.47%

DuPage County –

Total Cases in Last Seven Days: 3,402

Cases Per 100K Residents: 368.61

Positivity Rate: 5.95%

Grundy County –

Total Cases in Last Seven Days: 325

Cases Per 100K Residents: 636.58

Positivity Rate: 12.56%

Kane County –

Total Cases in Last Seven Days: 2,016

Cases Per 100K Residents: 378.66

Positivity Rate: 7.75%

Kankakee County –

Total Cases in Last Seven Days: 561

Cases Per 100K Residents: 510.64

Positivity Rate: 11.44%

Kendall County –

Total Cases in Last Seven Days: 641

Cases Per 100K Residents: 496.94

Positivity Rate: 10.92%

Lake County –

Total Cases in Last Seven Days: 2,480

Cases Per 100K Residents: 356.05

Positivity Rate: 5.25%

LaSalle County –

Total Cases in Last Seven Days: 611

Cases Per 100K Residents: 562.26

Positivity Rate: 5.25%

McHenry County –

Total Cases in Last Seven Days: 1,662

Cases Per 100K Residents: 540.01

Positivity Rate: 8.14%

Will County –

  Total Cases in Last Seven Days: 3,089

Cases Per 100K Residents: 447.2

Positivity Rate: 8.22%

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