Middle East respiratory syndrome (MERS): A new zoonotic viral pneumonia

Cunha, Cheston B; Opal, Steven M

Nearly a decade following the SARS epidemic, a new coronavirus causing severe viral pneumonia in the Arabian peninsula has emerged, i.e., middle east respiratory syndrome (MERS). In June 2012, the index case of MERS-CoV occurred in Saudi Arabia. 3, 4 Since that time, according to the World Health Organization, there have been 688 confirmed cases and 282 deaths in 20 countries. Most cases have occurred in the Arabian peninsula, i.e., Saudi Arabia, United Arab Emirates, Qatar, Oman, Jordan, Kuwait and Lebanon. In addition, travel-related MERS cases have been reported from Europe (United Kingdom, Italy, Greece, Netherlands, France, and Germany) as well as Tunisia, Malaysia, Philippines, Egypt, and most recently Iran and the United States. The zoonotic vector and possible reservoir of MERS has been found to be dromedary camels, with bats as another possible vector for transmission to humans. 5 Although both SARS and MERS are caused by coronaviruses, SARS was characterized by efficient human transmission and relatively low mortality rate while MERS is relatively inefficiently transmitted to humans but has a high mortality rate, i.e., 35-50%. 6 In terms of virulence, MERS most closely resembles pandemic influenza (H 1 N 1 ) and avian influenza (H 7 N 9 ) not SARS, but MERS potential for widespread transmissibility is less than avian influenza (H 7 N 9 ).