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Confidential statewide coronavirus outbreak data shows workplace, school and prison outbreaks are driving the increases — and that many of these outbreaks have never been made public. (Photo: wellesenterprises / Getty Images)

Like many Midwestern states, Illinois has struggled with rising coronavirus cases and death counts recently, surpassing 300,000 confirmed cases this month and recording its highest daily death count since late June on Friday. 

Public health officials issued a “warning list” for 28 Illinois counties at risk for coronavirus surges and blamed, in part, businesses who were “blatantly disregarding mitigation measures, people not social distancing, gathering in large groups and not using face coverings.”

Now, confidential statewide coronavirus outbreak data, obtained by the Documenting COVID-19 project at the Brown Institute for Media Innovation as part of a collaboration with the Midwest Center for Investigative Reporting, shows workplace, school and prison outbreaks are driving the increases — and that many of these outbreaks have never been made public.

The Illinois Department of Public Health, citing a state communicable diseases code, does not release details about where many outbreaks have occurred, limiting its disclosures to long-term care and assisted living facilities. Separately, the Illinois Department of Corrections and some county health departments regularly release numbers of infected inmates and prison staff. 

But the internal statewide data we obtained — prepared by the state health department and covering four different dates between July and September — gives detailed information and case counts for nearly 2,600 separate outbreaks across Illinois. 

“Even though they are close to it, sometimes the infected don’t know that there’s an outbreak where they work. It’s a problem,” said Dr. Michael D. Cailas, an associate professor of occupational and environmental health sciences at the University of Illinois School of Public Health, who reviewed the confidential state data for this story. Cailas, who has mapped Chicagoland long-term care outbreaks, added that many of the workplace outbreaks in Illinois are simply “not known” to the public.

In response to questions, the Illinois Department of Public Health said that it is bound by state and federal laws designed to protect the identity of those infected. “Another consideration is the fact that people may not have become infected at the business location,” said department spokesman Melaney Arnold. As part of its contract tracing efforts, the health department is compiling data on the types of facilities and locations where outbreaks are occurring and is “working to make this information available.”

The data shows:

The single biggest source of coronavirus infections in Illinois are federal, state and county prisons and jails. The Cook County Jail has 1,074 positive cases, the largest count of any single outbreak.

But significant outbreaks at other Illinois prisons, including Stateville Correctional Center in Crest Hill, near Chicago; East Moline Correctional Center in Rock Island; and Robinson Correctional in Crawford, brings the prison total as of Sept. 30 to nearly 3,400 cases across 27 different facilities. That’s nearly double the almost 1,800 prison figure for Illinois reported by the Marshall