The number of people being "actively monitored" by public health officials in Illinois sat at 286 as of Monday afternoon, according to the Illinois Department of Public Health.
IDPH Director Dr. Ngozi Ezike said that number will likely change, but noted that the group is being monitored to see if they develop symptoms of the novel coronavirus, also known as COVID-19.
"If they develop fever and respiratory symptoms and then get tested and then get confirmed that’s when we count them as a case," Ezike said.
It was not immediately clear if all 286 cases were under quarantine, but the number comes as a fourth patient in Illinois tested positive for the virus.
The woman is the spouse of a man who tested positive over the weekend in a Chicago suburb, the Illinois Department of Public Health said in a release.
Health officials said both patients, who are in their 70s, were in "good condition." The woman is being quarantined at home and "is complying with health officials."
"Public health officials are working to identify and actively monitor individuals who were in contact with both patients in an effort to prevent additional transmission," the Illinois Department of Public Health said in a statement. "Public health officials will reach out to individuals who may have been exposed."
Meanwhile, the hospital treating the woman's spouse, Northwest Community Healthcare in Arlington Heights, said Monday that he remains hospitalized in isolation.
Little information has been released about the couple, including how they may have been exposed or if they traveled within the Chicago area before becoming ill.
Northwest Community Healthcare said infectious disease specialists are at the hospital "working closely with communicable disease officials from the Cook County Department of Public Health, the Illinois Department of Public Health and the CDC."
"NCH is closely following recommended guidelines outlined by these officials," the hospital said in a statement. "At the moment we are implementing all associated protocols, including an exposure investigation, to identify those who might have had contact with this patient in order to treat them accordingly. Along with this patient, our top priority will remain to keep our staff and community safe at all times."
The latest case marks the fourth person in Illinois to test positive for the coronavirus, Cook County and state health officials said in a news release.
Ezike said the risk to the general public remains low, but it is also possible that more cases could arise.
"I want to be clear that the best thing that the general public can do at this time is to continue to take the same precautions you take during flu season with renewed vigilance," Gov. J.B. Pritzker said Monday afternoon, adding "people should not be overly concerned about this."
Though tests for the latest patients, which were conducted in Illinois, came back with positive results for the new coronavirus, COVID-19, the results for both have yet to be confirmed by the U.S. Centers for Disease for Control and Prevention, officials said.
Public health officials said they're working to identify and actively monitor individuals who were in contact with the patients in an effort to reduce the risk of additional transmission.
The state of Illinois also plans to ask the CDC to deploy a team for assistance.
School District 25 in the Arlington Heights said in a letter Sunday that two staff members and their children were contacted by a babysitter whose relative, a hospital employee, had been exposed to the coronavirus patient. The staff members and their children work at or attend Dryden, Ivy Hill, Greenbrier and Olive Mary Stitt schools, the district said.
Though none of the employees or their children have experienced symptoms, the district said the group was staying home to self-monitor.
"I’ve been working directly with the Cook County Department of Public Health (CCDPH) and the Village of Arlington Heights," Superintendent Lori Bein said in a statement. "CCDPH has informed me that there is nothing additional that District 25 should do at this time."
Bein urged students who are sick to stay home until at least 24 hours after they no longer show signs of a fever and reminded staff and families of basic health precautions to take, like washing your hands and covering your nose and mouth when coughing or sneezing.
Bein said she was sharing the information "to be proactive."
The Illinois Primary Health Care Association said the state's community health centers are working with the World Health Organization, the CDC and IDPH to "ensure accurate protocols and communication plans are in place."
"Health centers are educating their staff and patients about the prevention and spread of COVID-19 to help mitigate the risk of a potential spread," the association said in a statement.
In January, two Chicago residents, a husband and wife, were diagnosed with the coronavirus. The wife had recently traveled to Wuhan, China, the epicenter of the outbreak, to care for a relative.
Both patients were treated at AMITA Health St. Alexius Medical Center in Hoffman Estates and have since made a full recovery.
On Saturday, the new coronavirus claimed its first victim inside the U.S. as the White House announced additional travel restrictions on international travel to prevent its spread.
Last month, Illinois became the first state to conduct its own tests for the coronavirus, allowing for quicker results.
On Monday, officials said Pritzker requested that hospitals across the state implement additional testing to "improve surveillance for COVID-19." He also planned to add two more labs in central and southern Illinois that will test specimens this week.
The Illinois Department of Public Health launched a statewide hotline for the coronavirus, also known as COVID-19, "to answer any questions from the public or to report a suspected case," Pritzker said. That number is 1 (800) 889-3931.