MERS virus particles. Coloured scanning electron micrograph (SEM) of Middle East respiratory syndrome-related coronavirus (MERS-CoV) particles (virions, yellow) on infected cultured VERO E6 cells (blue). 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.