Unraveling the Mysteries of Middle East Respiratory Syndrome Coronavirus

Middle East respiratory syndrome coronavirus, or MERS-CoV, is a novel coronavirus known to cause severe acute respiratory illness in humans; about 40 percent of confirmed cases have been fatal. Human-to-human transmission and multiple outbreaks of respiratory illness have been attributed to MERS-CoV, and severe respiratory illness caused by this virus continues to be identified. MERS-CoV was first reported in September 2012, and subsequent investigations documented illness onsets as early as April 2012. As of February 23, 2014, the World Health Organization has reported 182 laboratory-confirmed cases of MERS-CoV infection, including 79 deaths, indicating an ongoing risk for transmission to humans in the Arabian Peninsula. The median age of reported case-patients is 52 years. The range is 2 to 94 years; most case-patients are male. Most index case-patients have at least 1 reported chronic comorbid condition and have resided in, or recently traveled to, Jordan, Qatar, United Arab Emirates, Oman, Kuwait, or Saudi Arabia. Confirmed cases of MERS-CoV have been identified in travelers returning from France, Germany, Italy, United Kingdom, and Tunisia. Although some have speculated that a zoonotic reservoir of MERS-CoV exists, very little is known about the specific exposures that result in primary human cases.