University of Illinois rolls out new test as state reports almost 2,000 more COVID-19 infections

New cases of COVID-19 rose by 1,953 Thursday, the highest daily tally since May 24, officials said, as University of Illinois Urbana-Champaign scientists ramp up a saliva test to detect the virus they hope will be game-changing.

Twenty-one more residents have died from the respiratory disease, the Illinois Department of Public Health reported. That puts fatalities statewide at 7,594 and total infections at 188,424.

The state's COVID-19 test positivity rate increased to 4% based on a seven-day average. There have been 2.93 million virus tests performed so far.

Daily tests reported Thursday reached 41,686 for a daily positivity rate of 4.7%. That rate has bounced around this week, including a 3.5% rate Tuesday.

Amid concerns about a rising tide of cases, the University of Illinois at Urbana-Champaign is providing some optimism as the campus pioneers a test that's noninvasive and provides a quick turnaround, researchers said.

Up to 40 testing stations, typically in large outdoor tents, have been erected to accommodate a projected 10,000 students (plus faculty and staff members) per day for saliva tests.

Walk-up tests are already being administered on campus, but a massive ramp-up is planned for Aug. 24 when fall classes resume. The plan is to test everyone on campus twice a week.

"It's free, they scan their ID card, get a tube and drool a small amount of saliva into the tube," said U of I chemistry Professor Paul J. Hergenrother, one of the scientists who developed the test. Saliva samples are heated, and subjected to a molecular chain reaction (PCR) test that shows the presence of COVID-19 genes, and results usually are available in five to six hours.

The virus is mainly spread through droplets when people cough, sneeze or speak, so "it makes sense to test the fluid which is responsible for lots of infections," Hergenrother said.

The news comes amid frustrations over lengthy delays in getting back COVID-19 test results nationwide.

The vast majority of COVID-19 tests in Illinois involve sticking a nasal swab into both nostrils, then sending the swab to a laboratory for processing. The sample is transported in a special liquid, and lab technicians use chemicals to isolate a cellular acid known as RNA that identifies viruses.

Supply shortages and logistics, depending where the lab is located, have resulted in some people waiting days and weeks for results.

"This bypasses the supply chain bottleneck," Hergenrother said. "We built out our own on-campus testing facility, which is key to enabling reporting results back very quickly."

Comparisons of saliva tests with nasal swab tests have been promising, with both methods detecting the same positive tests out of 100 samples, researchers reported in preliminary findings. The cost, about $10 a test, is cheaper than the standard swab test, which is $100, according to Science magazine, which highlighted the U of I findings.

A fast test that's easy to repeat could be a huge break for schools and workplaces seeking to reduce virus exposure.

The state offers free nasal swab tests at 11 locations and at mobile sites, which generally produce results in three to seven days or faster, an IDPH spokesperson said.

Test sites in Illinois range from public centers to private clinics, and the labs used to process samples may be local or located elsewhere in the U.S. "We have heard everything from two to three days at local commercial labs (for test turnarounds) and up to eight to 14 days at larger national laboratories," the IDPH said.

Gov. J.B. Pritzker said Tuesday the state is "talking to the University of Illinois about how we might provide that (test) across the state to other locations."

Given that U of I researchers first published their findings in June, it's been a fast-paced summer, Hergenrother said. "We're not declaring victory yet," he said. "We set out to make a difference and help our own institution. We're really, really hopeful this will be adopted by others."

A total of 1,517 patients were in Illinois hospitals with the virus as of Wednesday night, 73 more than the seven-day average of 1,444.

Hospitalizations and positivity rates are two important metrics health experts watch. If sustained spikes occur in any of 11 state regions, the state will clamp down on activities where people come together ranging from indoor dining to group gatherings, Pritzker has warned.

On May 24, the IDPH reported 2,508 COVID-19 new infections, but those numbers began to taper off in June and fell into the hundreds per day.

Easing restrictions, such as allowing movie theaters to open, began June 26, and daily caseloads have gradually increased.

The seven-day daily average of new cases stands at 1,646, compared to 1,424 for the period of July 24 to July 30.