An acronym for Middle-Eastern Respiratory Syndrome, a condition caused by a coronavirus and resulting in severe ACUTE respiratory symptoms with evidence of pneumonia or ACUTE RESPIRATORY DISTRESS SYNDROME (ARDS). It occurs in epidemics, particularly when large numbers of people are in contact, for example during the Hajj. Thus, in Saudi Arabia in 2015, there were over 1,200 reported infections and 521 deaths, with onward transmission of infection to 21 countries. There is no specific treatment beyond any necessary intensive care.