Since the pandemic began, 10 Illinois schools have reported confirmed coronaviurs outbreaks and 478 have reported exposures, according to data from the Illinois Department of Public Health.
Through exposure data from contact tracing at local health departments, Gov. J.B. Pritzker said the state has recorded 10 schools out of 5,478 with confirmed COVID-19 outbreaks.
Of the over 5,000 schools in Illinois, 478 have reported potential COVID-19 exposures, meaning the schools are locations where the coronavirus may have occurred, but are not definitive exposure or outbreak locations.
"Anyone who goes into a school building regularly would have likely reported school as a place they went before they were confirmed positive – that doesn’t at all mean that school is where they contracted the disease originally," Pritzker said.
Pritzker noted that local health departments will likely provide more specific data that the Illinois Department of Public Health on each individual school's outbreak or potential exposure.
The outbreaks do not include secondary cases where a member of a household contracts the coronavirus but has not been on school grounds, according to Pritzker. However, he said the data does include cases associated with before and after school programs, such a sports.
Pritzker clarified the difference in meanings between outbreak and exposure, as the two words have "very specific, distinct meanings in public health."
"The location of an outbreak is more difficult to identify than the location of an exposure," Pritzker said. "An outbreak is defined as five or more cases that are linked to a specific setting during a 14-day period."
Linked cases must be from different households, according to the Illinois governor, and not also connected to other sources of the virus.
With frequently visited places, such as restaurants and grocery stores, outbreaks are not as easy to determine as an exposure to the coronavirus, Pritzker said.
He added that factors such as the disease being respiratory and later onset of symptoms add to the difficulty of declaring official outbreaks of COVID-19.
"Much more useful is exposure data – particularly for the average person who wants to design their day to day in a way that reduces the most risk," Pritzker said. "Exposure data comes from contact tracers talking to confirmed positive COVID patients about the places they went in the time before they were symptomatic or tested positive."
Pritzker explained that exposure data is more useful because it gives a sense of where people are at greatest risk for contracting coronavirus and where transmissions is highest in the state.