The number of confirmed COVID-19 cases in Illinois spiked by 80 percent, Gov. JB Pritzker announced Wednesday, with ominous forecasts from the top public-health official in his cabinet that those numbers will continue to increase rapidly as the state’s testing capacity expands.

At a briefing in far downstate Murphysboro, site of one of the state’s COVID-19 testing labs, Pritzker announced 128 new cases of the highly contagious and sometimes lethal virus. That total included 20 more people testing positive at a quarantined DuPage County nursing home, where the total number of diagnosed residents and staff stands at 42.

The new surge brings Illinois’ total number of COVID-19 cases to 288 in 17 counties. That total includes one death.

“I’m not saying this lightly, but unfortunately the grim truth is that these numbers will continue to grow significantly as will likely the unfortunate statistic of fatalities,” state Public Health Director Ngozi Ezike said.

In other headlines from Wednesday’s briefing, Pritzker also said his administration has increased the state’s testing capacity and is mulling a possible early release of some non-violent prisoners to minimize the chance of outbreaks at densely populated state prisons. The state also has activated members of the Illinois National Guard to help build temporary medical facilities near hospitals to treat the exponentially growing COVID-19 caseload.

Pritzker also even left open the possibility of more restrictive orders against public gatherings when asked about a potential lockdown like those seen in places like Italy.

“What I would say is that we should look at the mistakes that were made in Europe as this crisis was coming upon them, as this coronavirus was spreading,” Pritzker said. “And we should, it should be a cautionary tale to all of us that we need to make sure that we’re distancing ourselves, socially distancing ourselves, that people are isolating themselves when they feel that they might have even a cold.”

With people off work and at home and store shelves being emptied of many household staples, Pritzker said all steps would be made to assure that the public’s access to food, prescriptions and fuel won’t be disrupted.

“Essential services will always remain available,” Pritzker said. “Grocery stores, pharmacies, gas stations — the things we all need — will not be closing down.”

Pritzker said the state continues to expand its testing capabilities, but there still is not enough capacity to meet expected demand. Through Wednesday afternoon, more than 2,000 tests had been administered statewide, according to a new state coronavirus website Pritzker debuted.

“I just heard that one of our labs today at 12:30 received the ability to do thousands more tests because of work done by our staff. And so I’m happy to say that we’ll be able to do more tests,” the governor said. “It’s still not enough, to be clear. You talk about thousands of tests – we need to be able to test many more people than that.”

Both Pritzker and his public health director continued to stress that older adults,and children and teens who are out of school need to stay at home to protect themselves and slow the spread of the illness. Adults over 60 are among the most susceptible to contracting severe cases of COVID-19.

And in all cases when someone has cold or flu symptoms, do everything possible to avoid seeking hospital care unless the situation is dire, Ezike said.

“If you can stay home and weather it out, you are doing a tremendous part in creating a bed for someone who truly needs it and whose life needs to be saved,” she said.

In another development, Pritzker said his administration is weighing the possible early release of non-violent inmates from state prisons to lessen the chance of dangerous and debilitating outbreaks at those institutions, though no decision has been made to do that yet.

“There are some very dangerous people who should not be considered but there are others that are very vulnerable and who have committed some non-violent offense and who should be first in line if we were to do something like that.”

The governor said another vulnerable population the state is trying to protect is the homeless. Pritzker said the Illinois Emergency Management Agency is in talks with counties across the state about finding housing options for homeless people who have had contact with others who have COVID-19.

“We’re talking about facilities where we may need to isolate people who have been identified as being near someone,” the governor said.

Pritzker also made a pledge to assure that basic public transparency laws would not be rolled back in this time of crisis. An earlier executive order he signed relaxed attendance requirements at public meetings covered by the state Open Meetings Act, but the governor said he continues to honor the state open-records law, the Freedom of Information Act.

“We’ll continue to respond to FOIA requests,” Pritzker said, but added, “I would ask for people to have some patience.”

And in a new sign of the serious economic toll the pandemic is having on the state’s workforce, unemployment insurance filings are skyrocketing, according to the Illinois Department of Employment Security.

“Over the last two days,” agency spokeswoman Rebecca Cisco said, “IDES has received over 41,000 unemployment benefit claims, as compared to the same two days during the corresponding week last year, when IDES received 4,445 unemployment benefit claims.”

The likelihood of any sort of legislative relief in response to the COVID-19 crisis won’t be coming imminently. Pritzker Wednesday said he would leave it to legislative leaders about when all 177 House and Senate members should return to Springfield, along with hundreds of staffers and lobbyists. Pritzker cited logistical issues in following federal public-health recommendations to restrict contact with more than 10 people at a time.

“We need to make sure we’re doing this in a way that’s healthy and safe,” the governor said.

As the governor was responding to the question about the state legislature, the Illinois House cancelled next week’s four-day work week. The state Senate was scheduled to be in during that time, as well, but no scheduling decisions had been made pending a teleconference among Senate Democrats, said John Patterson, a spokesman for Senate President Don Harmon, D-Oak Park.

Dave McKinney and Tony Arnold cover state government and politics for WBEZ. Follow them on Twitter @davemckinney and @tonyjarnold.