MERS coronavirus particle. Transmission electron micrograph (TEM) of a section through a Middle East Respiratory Syndrome Coronavirus (MERS-CoV) particle (virion, round). Formerly known as novel coronavirus, MERS was first identified in Saudi Arabia in 2012. Most people infected with MERS develop severe acute respiratory illness with symptoms of fever, cough, and shortness of breath. As of May 2014, there have been 571 confirmed cases including 171 deaths. The virus has been reported in 18 countries.