Mayor Lori Lightfoot on Thursday ordered all Chicagoans with confirmed cases of coronavirus — as well as those just exhibiting symptoms of the highly-contagious disease — to stay home to prevent community spread of the pandemic.

The mayor took the unprecedented step after Health Commissioner Dr. Allison Arwady signed a public health order stating that those with confirmed cases or symptoms “may not leave their homes, go to work or meet in groups.”

The only exception to the stay-at-home order is to seek “essential services, including necessary clinical care or evaluation and life sustaining needs” that include “obtaining food and medicine.

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Violators will be slapped with citations and fines by Chicago Police and the Department of Public Health, even though it’s not known precisely how they will be identified.

“We have repeatedly asked throughout this crisis that, if you are sick, stay home. Most of you have listened, but some have not. And those of you that have not, have not only put yourselves at risk, you are endangering the public,” Lightfoot said during her TV address.

‘We have documented an increasing number of cases in which sick people, went to their workplace, and got other people sick with the coronavirus.”

Lightfoot said the order issued at her direction will mandate what some Chicagoans who have tested positive for coronavirus and those with symptoms have refused to do on their own.

“Until further notice, if you are sick with respiratory symptoms like cough, fever, or shortness of breathe, but also, and importantly if you are beginning to feel sick — body aches, fatigue, sore throat — you, too, are ordered to stay home unless seeking medical care, or other essentials like food,” the mayor said.

“If you violate this order, there must be consequences. Be smart, be safe, and stay home if you are sick. That’s an order.”

Lightfoot said she’s well aware that the restrictions she imposed are “causing hardships.” But, she said she is “doing this to save lives — pure and simple.”

“We have seen what these extreme measures have yielded in places like Japan and Singapore. Those countries have started bending the arc of the virus. And China is reporting progress for the first time. These measures work and we need them now as this virus progresses here in Chicago.”

The stay-at-home order will remain in place until Arwady makes a written determination that the threat to public health posed has diminished, City Hall said.

The order defines “COVID-19 Illness” as “demonstrating symptoms of acute respiratory disease, including, but not limited to, new onset of fever, cough, shortness of breath, congestion in the nasal sinuses or lungs, sore throat, body aches, or unusual fatigue.

It states that patients must be “free of fever,” described as a body temperature of 100.4° Fahrenheit or greater , “and any of the other symptoms described herein, for at least 72 hours, without the use of fever-reducing or other symptom-altering medicines that include cough suppressants.”

Lightfoot has already canceled the St. Patrick’s Day Parade and Wednesday’s City Council meeting in response to a pandemic that has closed schools, bars and dine-in restaurants and has turned downtown Chicago into a ghost town with most employees working from home.

She has closed 60 public libraries, ordered a temporary moratorium on ticketing, towing, booting and debt collection to ease the financial burden on Chicagoans and promised more specific financial relief for restaurant workers and other hourly workers most impacted by the pandemic.

The police academy has also been closed, temporarily shutting down training needed to comply with rigorous requirements of a federal consent decree and churn out police recruits. For the time being at least, recruits have been transferred to police districts.

Already, an employee of the city’s Department of Procurement Services and three first responders — a Chicago Fire Department paramedic, an assistant deputy chief paramedic and an unspecified Chicago Police Department employee — have tested positive for the virus.

The Police and Fire cases are particularly troubling because of the threat of a more rampant spread that could sideline a large group of first-responders just when they’re needed most.

The name, rank and position of the CFD employee were not disclosed.

Police Department spokesman Anthony Guglielmi said only that the impacted employee is at home under quarantine, that CPD “began a thorough cleaning and disinfection of the facility where the employee was stationed” and officials are working to identify anyone who may have interacted with that employee.

Dr. Howard Ehrman, a former assistant commissioner of the Chicago Department of Public Health, said the mayor’s order doesn’t go far enough and could put people in danger.

“Stay in your house if you’re sick and you’ve got symptoms, but nobody will come test you,” Ehrman said, mocking the directive. “If you really feel sick, then leave your house, take two buses, go to the closest emergency room and maybe you’ll get tested there.”

Ehrman said the city should set up a 24-hour hotline that Chicagoans seeking in-home treatment can call to talk to a nurse. If a caller is displaying certain symptoms, a health care worker could then be dispatched to their home to administer a test at the door.

Given that the city likely doesn’t have enough employees to handle that response, Ehrman holds that CDPH Commissioner Allison Arwady could quickly deputize medical students to perform the tests. In Italy, Europe’s coronavirus epicenter, thousands of students are currently being fast-tracked as doctors to help respond to the crisis.

Ehrman said encouraging sick people to leave their home for treatment is counterintuitive.

“All it takes is for one person to be positive and then you’ve got several more hundred people that potentially are positive,” he said. “But even if you have your own car and you go to the best place in town, you could come into contact with other people.”

Should a person with coronavirus symptoms breaks quarantine, they still may not be able to get a test. While some private hospitals have started administering tests and the Illinois Department of Public Health expanded its guidance on who can get one, there’s still a shortage of testing kits and other supplies needed to process them.

“This is the whole insanity of what’s going on now without having enough of these tests. You get in these crazy conundrums,” said Dr. Robert Murphy, executive director of the Institute for Global Health and Northwestern University.

Determining how many people have the disease is critical for stopping the spread, said Murphy, who pointed to countries in Asia that have been able to vastly expand their testing capabilities. He noted that South Korean health care workers have effectively used drive-through labs to help test around 15,000 people a day, nearly 5 times the amount of tests Illinois has run altogether.

Though Northwestern Memorial Hospital and other medical centers have started conducting drive-through tests, there are still limitations. At Northwestern, a patient needs an order from a doctor.