An Illinois man has become the third person in the United States infected with the virus that causes a deadly disease and has killed dozens of people around the world, federal officials said Saturday.

The unidentified man is a work associate of the first U.S. patient to have been diagnosed with the Middle East Respiratory Syndrome (MERS), the Centers for Disease Control and Prevention said in a statement. The first patient lives in Indiana.

While a blood test showed the Illinois patient was infected with the virus, he has not shown any symptoms and has not needed any medical care.


“This latest development does not change CDC’s current recommendations to prevent the spread of MERS,” David Swerdlow, who is leading CDC’s MERS response, said in a statement. “It’s possible that as the investigation continues others may also test positive for [the virus] but not get sick.

CDC said the Illinois man probably got the virus from the Indiana patient and developed antibodies to fight it. 

The Indiana patient had recently traveled to Saudi Arabia, where the bulk of the MERS cases have been diagnosed. But the Illinois man did not travel to the Middle East.

CDC confirmed Indiana MERS case earlier in May, making it the first case in the country. That patient was released from the hospital May 2. The second case came Monday in Florida.

As of Friday, health officials have confirmed 572 cases of MERS in 15 countries, and 173 people have died, CDC said.

The disease has caused respiratory illness with fever, cough and shortness of breath. It was first diagnosed in Saudi Arabia in 2012.