(CNN) -- Two health care workers went to the emergency room with flu-like symptoms after coming into contact with a patient confirmed to have Middle East Respiratory Syndrome, or MERS, officials said Tuesday. The Florida patient represents the second confirmed case of MERS brought into the United States, the Centers for Disease Control and Prevention said Monday. MERS is a mysterious virus that can be fatal, and was first found in the Arabian Peninsula in 2012. One health care worker in Orlando began showing symptoms 72 hours after exposure to the MERS patient but did not meet criteria for admission and was sent home, said Dr. Antonio Crespo, an infectious disease specialist at Dr. P. Phillips Hospital, where the MERS patient is being treated. The health care worker will be monitored and seems to be improving, Crespo said.
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NEW: TSA will put up advisories about MERS in airports
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Two cases have been confirmed in the U.S.
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At least 20 health care workers told to not come to work
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They can return to work after 14 days if medically cleared
The U.S. @placeholder will post CDC advisories at more than 20 U.S. airports to alert travelers about the virus.