A virus called coronavirus is the cause of MERS. There are many kinds of coronavirus, some of which cause the common cold. The MERS coronavirus (MERS-CoV) was a new variant that was discovered in 2012 in the Middle East region.
How MERS spreads is not completely understood, but experts believe that the main way it spreads is through close contact with an infected person (by caring for or living with the person, or having direct contact with their respiratory secretions and body fluids). The people who have been infected by MERS have all been in a health care facility or among close family members.
MERS is different from SARS. Most importantly, the MERS virus does not appear to be as easily spread between people, whereas the SARS virus spreads very easily.