The new virus is only the seventh identified coronavirus that can infect humans. According to the Centers for Disease Control and Prevention, symptoms of common coronaviruses include runny nose, headache, cough, sore throat and fever. However, more severe coronaviruses can cause illnesses like severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS).
The CDC confirmed Tuesday that the first domestic case of the coronavirus has been detected in a patient in Washington State who had recently traveled to China.
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Coronaviruses are a large family of illnesses that cause a variety of upper respiratory infections. Doctors say the virus can mimic the flu.
Hospitals across Chicago are screening patients with flu-like symptoms for the virus. At O'Hare they are also screening international travelers for symptoms.
"Any traveler who screens positive for potential illness would not pass through the general airport population," said Dr. Allison Ardaway, Chicago Department of Public Health.
Passengers arriving at O'Hare have been vigilant about the virus, some avoiding Chinese airports of concern.
"I just canceled that flight, and I changed it to another flight, like come from Shanghai," said Guy Xie, traveler.
Screening is also taking place as passengers leave China.
A passenger arriving on a United flight from Shanghai said a doctor had to treat two passengers on his United flight who were ill.
"I came out and asked the doctor whether this was one of those cases and he said 'I do not know. We are checking,'" said the passenger, who asked to remain anonymous.
United Airlines released a statement, saying, "The safety of our customers and employees is our top priority. Health officials met United flight 836 upon its arrival at Chicago O'Hare earlier today and met and released two passengers. We continue to follow CDC guidelines and remain in close contact with authorities in the United States and Asia to further ensure the safety of our customers and employees."
Chicago health officials said they are not advising travelers to change their behavior at this point, nor are they advising airport employees or vendors to take any protective measures.
"There should be no panic. People should not panic. We are really looking at a discrete population," said Dr. Sharon Welbel, Cook County Health Department.
At Elmhurst Hospital doctors focused on travel history to determine if the patients are at risk.
"Anyone that has a respiratory illness, we do ask if they have traveled recently," said Dr. Angela McCormick. "Specifically, in the last two weeks, if they have been to China."
Elmhurst Hospital said they have not seen the specific strain of the coronavirus that has been spreading through China, but since December they three patients have tested positive for an unknown strain.
"We are only seeing 2 percent come back positive for the coronavirus, but this is an unnamed strain, on the one from China," McCormick said.
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More than a dozen health care workers in China contracted the virus after treating an infected patient. The number of cases has now risen to 440 and the death toll has risen to nine.
Deputy Director of the National Health Commission Li Bin told reporters on Wednesday that the figures were current as of midnight Tuesday and all the deaths had been in Hubei province, where the first illnesses from the new coronavirus were reported in December.
Scientists recently announced the virus spreads from human to human, not just animals as first believed. U.S. officials are working to detect and stop the spread of the coronavirus, and doctors are urging everyone to do their part. To prevent transmission, hands should be washed frequently and patients should wear a mask.
Late last week, U.S. health officials began screening passengers from central China at New York, Los Angeles and San Francisco airports. Officials around the world have implemented similar airport screenings in hopes of containing the virus during the busy Lunar New Year travel season.
Tuesday, the CDC announced that Atlanta and Chicago O'Hare airports would also begin screening travelers. The CDC said these airports see the highest volume of passengers coming from the Wuhan area to the US. According to the CDC, approximately 1,200 passengers have been screened for signs of illness since Friday. No passengers have been sent to the hospital as a result of these screenings.
The Associated Press contributed to this report.