The virus, known as a coronavirus, that has now been shown to transfer from person to person, rather than from animals to humans, is part of the same family of viruses as the one that caused Severe Acute Respiratory Syndrome which killed 775 people in 2003.
According to the CDC's Morbidity and Mortality Weekly Report, the coronavirus spread from a 60-year-old man who lives in the United Kingdom and recently traveled to the Arabian Peninsula to two members of of his family. The virus caused respiratory illness in all three, killing one.
The CDC report urged healthcare professionals to be on the lookout for unexplained respiratory illnesses, particularly in people who or were in contact with a person who recently traveled to the Middle East.
No cases have been reported in the U.S. so far.