Ann Saudi Med 2013 September-October www.annsaudimed.net 427 The emergence of a novel human coronavirus recently renamed the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) from the Arabian Peninsula has created global alarm because it is the causative agent of a severe and frequently fatal acute respiratory illness (SARI) resembling the illness caused by severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV).1-4 The case fatality rate (CFR) in patients infected with MERS-CoV is high—estimated at 43% in 147 patients reported so far by World Health Organization (WHO).3 This rate is higher than that of SARS—estimated at 15%, and is strongly ageand sex-dependent.4 Although the source of virus in patients with sporadic infection remains unknown, it appears likely to be some species of animal.4,5 Clear evidence of limited human-to-human transmission of MERS-CoV has now been documented in several case clusters, including particularly family members and patients in health care facilities,6-8 but all such clusters have, at least thus far, been limited in extent. However, a real concern persists that the virus will adapt to interhuman transmission and switch from an aborted epidemic to a pandemic similar to the SARS-CoV epidemic in 2003–2004. MERS-CoV is transmitted through droplets and contact. In the case of invasive respiratory procedures, MERS-CoV is transmitted through airborne route.2 Early diagnosis and strict implementation of the core components for infection prevention and control programs are crucial for preventing epidemic amplification.2 In the absence of an effective vaccine and a specific antiviral treatment, there is an urgent need to rapidly identify potential therapeutics.