Across the country, states have either delayed reopening or reimposed restrictions amid surges in COVID-19 cases that have begun packing hospitals.
Waiting on the sidelines, at least for now, is Illinois, where health officials are watching daily statistics uneasily as the state continues to allow its residents more freedom to travel, visit and shop.
Those statistics offer some good news for Illinoisans, at first blush: We’re far below peak case levels, and not even close to being as bad as the most struggling states. For example, Arizona’s rate of new cases, relative to the state’s population, is more than seven times Illinois’.
The bad news: Illinois’ big drops of late May and early June are history — and some daily metrics are increasing. As the state continues to uncover hundreds of new cases a day, at least one researcher said the state should consider adding more restrictions until it’s clear what’s going on.
People wait in line at a free COVID-19 testing site provided by United Memorial Medical Center on June 28, 2020, at the Mexican Consulate, in Houston. Confirmed cases of the coronavirus in Texas continue to surge. (David J. Phillip / AP)
“It’s (at) a level of concern that, if we didn’t change what we’re doing now, that we could be headed toward a Texas or Arizona sort of situation,” Jaline Gerardin, a Northwestern University assistant professor of preventive medicine who works on virus modeling, said in an interview Thursday.
She offered that assessment even before numbers rolled in from the holiday weekend that further cemented a rise in the number of Illinois’ daily cases. State and local officials have said they’re monitoring all the data but haven’t announced major rollbacks to reopening.
Nearly four months into the pandemic, authorities cannot say, with relative certainty, how much and how quickly the virus has spread. Researchers say we don’t have the type of widespread and frequent (and expensive) testing that could best tell us just how deeply the virus has invaded different communities, and whether it’s dying out or coming back.
Here’s some information to help gauge how the state is doing:
Where are we on ‘the curve’?
For months, officials were all about bending the curve, typically defined as slowing the growth in case counts. It took a while, but it happened, to the point that new daily cases dropped even as more people took tests.
That was a great sign the virus was in retreat in Illinois. But now, daily case numbers are slowly rising again. That’s true even when those figures are averaged over seven days, which is a way to smooth out daily ups and downs so overall trends are easier to see.
The average rose from 598 on June 20 to 772 on July 3 — the most recent day an average could be computed from Illinois Department of Public Health figures.
And, if you dig deeper into June’s numbers, it appears they are increasing across the state, which makes this rise different than the first one, which was almost entirely fueled by cases in the Chicago area. As of July 3, nearly as many cases a day were added downstate (202 on average) as in Chicago (217).
Chicago measures its cases differently than the state. (The state counts a confirmed case on the date the test results come back. Chicago counts it on the date the test was taken, no matter how long the results take.) But even Chicago’s own case curve, also based on a seven-day average, shows a small uptick in late June.
How do Illinois cases compare?
Illinois’ boost in cases can leave researchers and officials feeling uneasy. But the state still appears in far better shape than some parts of the country.
One way to compare states is by taking the average number of new cases over seven days and converting that figure into a rate, such as the average per 100,000 residents. (That way, bigger states can be more fairly compared with smaller states.)
By that measure, Illinois’ rate of daily cases — 6.3 per 100,000 residents — puts it among the lower half of states. Ten states have rates above 20. And the worst states, Arizona and Florida, have rates more than six times as high as Illinois’.
These figures were computed with the help of data collected from the COVID Tracking Project, a national volunteer group. A separate compilation, from a coalition of researchers including the Harvard Global Health Institute, shows similar results for Illinois. Those researchers put Illinois in the second best of four groups of states. (That website also offers county case metrics, as does a separate website run by the Illinois Department of Public Health that displays older but more comprehensive data.)
Illinois excels on positivity rate
When case rates jump, a natural question follows: Is it just because we’re testing more? After all, the White House has argued that case figures are up across the country merely because people are taking more tests.
That argument can be addressed by another metric, the positivity rate. In essence, out of everyone tested, it’s the percentage testing positive. (So if 100 people are tested, and 10 test positive, the positivity rate is 10%.)
As a pandemic is brought under control, researchers say the positivity rate should drop even as more people are tested. The World Health Organization recommends a rate below 5% (among other metrics) for a region to consider loosening restrictions on movement. Researchers from the University of Illinois have said a 3% rate or lower suggests a region likely has the spread under control.
Here’s where the recent spikes across the country alarm researchers. Not only are case counts going up, but so is the positivity rate. For example, the states now with the highest rate of new cases — Arizona and Florida — have also seen massive jumps in the proportion of tests coming back positive since May: from 4% to 19% in Florida, and 6% to 26% in Arizona.
But this also is where Illinois stands out, for now. It’s one of 17 states with a positivity rate below the 3% threshold.
And Illinois’ good showing can be found across the state. Downstate Illinois’ positivity rate remains well under 3%, and the suburbs and Chicago have hovered close to 3% since mid-May. In essence, at least in Illinois, case counts have gone up, but the positivity rates have remained flat.
Still, this metric doesn’t end the debate. That’s because testing, in general, is not based on robust, random samples, which — while expensive — could offer more accurate predictions on the virus’s spread.
Illinois officials recognize this. A team from the University of Chicago and Northwestern University has suggested a slimmed-down plan to spot outbreaks sooner by testing small groups continuously, such as women giving birth. The state said it wants to incorporate the concept into a broader testing boost.
But for now, either people choose to get tested or it’s a condition of employment. Both of these factors can obscure the pandemic’s true trends. (Just ask Cass County, the only place pegged as worrisome in a recent state scorecard. Its figures jumped because the residents and workers at a nursing home were tested.)
Hospitalizations level off
Thankfully, most infected people aren’t sick enough to need to be hospitalized. But hospital data offers a consistent barometer of the unlucky number who have.
The state tallies the number of patients each day in a hospital who either have tested positive for the virus or are suspected of having it. The average COVID-19 bed count dropped from a high of 4,822 on May 1 to 1,448 on July 2.
But the way it has dropped has fueled concern. Much like the case data, the trends have begun to flatten in the last couple of weeks.
Northwestern’s Gerardin has access to more detailed and timely state data, as part of her role helping the state develop virus forecasts.
She said last week that some parts of Illinois were showing upticks that, while not severe, concerned her, particularly with the increase in positive tests. That’s because Illinois, even after new cases had dropped considerably, was never really able to squelch the virus so only a handful of cases remained.
“If we saw the same uptick, but we had eight cases and not 800, then I would feel differently,” she said. “A 10% increase from eight cases would not be as alarming as a 10% increase in 800 cases. That’s more transmission from a lot of COVID (cases) than more transmission from a tiny bit of COVID.”
And, when looking at hospitalizations, Illinois does not compare as favorably with other states, at least by one measure. When averaging COVID-19 bed counts in the seven days ending July 5, the most recent comparable data, Illinois is among the highest third of states, even after adjusting for population.
Illinois’ rate, at 11.5 beds occupied per 100,000 residents, is not much lower than those in other states in the headlines now, such as California at 17, though it is still far less than Arizona’s 40. One caveat: Three states haven’t consistently reported hospitalization data, including Florida, which is seeing a major surge in reported cases.
On the other hand, when you look at whether bed counts are going up or down, Illinois is among those showing declines. But this measure by its nature is based in part on older data. (It compares the most recent average of hospital beds used with the average from a week prior.) And we know that, whatever Illinois’ past achievements, its hospitalizations appear to have leveled off.
Still, many other states saw increases last month, including neighboring Missouri, where the figure rose roughly 24% from week to week. Even steeper spikes were seen in 10 other states, including Georgia (42%) and Texas (53%). (Again, Florida is among three states without data to report.)
One more way to look at Illinois’ place in the pandemic is to chart its case curve against those of other large states: California, Florida, Pennsylvania, New York and Texas.
Illinois has the country’s sixth-biggest population, and (as noted above) is seeing its rolling average of new cases trend slightly upward. But its case curve has evolved far differently than the other states.
Early in the pandemic, New York was the epicenter of new cases. When New York bent its curve downward, Illinois briefly led this group of states on number of cases, before beginning its own drop.
Three other states, however, couldn’t contain their case growth. By late May, California passed Illinois on average daily count. A week later, so did Texas and, days later, Florida.
Now those three states have average daily case counts more than eight times Illinois’ average cases.
California, Texas and Florida are among the 15 states that Chicago Mayor Lori Lightfoot cited when she required travelers from those places to quarantine for two weeks, starting Monday.
Ultimately, Illinois’ fate in this pandemic remains murky.
Because of the lag time between someone getting infected, then tested, then receiving lab results and (potentially) becoming ill enough to be hospitalized, Gerardin said Thursday that the statistical upticks Illinois is seeing now may be attributed to the tail end of the third phase of reopening, with even more, yet-to-be-recorded cases likely resulting from the eased restrictions in phase four.
When asked if there was reason for concern, she offered a quick and resolute answer: “absolutely.”
“The big picture is that we’re not out of the woods,” she said.
