As of 15 May 2013, WHO had been informed of a global total of 40 laboratory-confirmed cases of human infection with novel coronavirus, including 20 deaths, in 6 countries: France, Germany, Jordan, Qatar, Saudi Arabia and the United Kingdom.

Standardized name

Since the discovery of the virus, scientific literature, databases and the media have used various names for it. To provide uniformity and facilitate communication about the disease, the Coronavirus Study Group of the International Committee on Taxonomy of Viruses has decided to call the new virus Middle East respiratory syndrome coronavirus (MERS-CoV). WHO and other Committee members strongly urge the use of this name in scientific and other communications. The standardized name was announced in the “Journal of Virology” on 15 May.

Morbidity

Although the number of cases documented is limited, the morbidity and mortality from MERS-CoV infection are alarming. A few of the known cases developed mild disease, but most patients have presented with a severe acute respiratory condition requiring hospitalization, and half have died.

Geographic spread

So far, the infection appears to be geographically linked to the Arabian Peninsula. Two small clusters of human-to-human transmission, from imported cases with travel history to the Arabian Peninsula, have been observed in Europe: in United Kingdom (2 cases) and in France (1 case).

Transmission

Saudi Arabia informed WHO of two laboratory-confirmed cases in health care workers who were exposed to patients with confirmed MERS-CoV: a 45-year-old man, who became ill on 2 May 2013 and is in a critical condition, and a 43-year-old woman with a coexisting health condition, who became ill on 8 May 2013 and is in stable condition. Although health-care-associated transmission of the virus had previously been observed in Jordan in April 2012, this was the first time that health care workers had been diagnosed with MERS-CoV infection after exposure to patients. Concern remains that the virus may adapt to efficient human-to-human transmission. WHO continues to monitor the situation closely.

Source of infection

The source of infection is not yet known. Based on what is known about coronaviruses in general and the accumulating evidence on this virus, MERS-CoV appears to have originated in bats. It is likely that a single variant from bats crossed over to an intermediate animal host species (at least in the Middle East), however, and subsequently infected the human population.

WHO recommendations

Based on the current situation and available information, WHO encourages all Member States to continue their surveillance for severe acute respiratory infection (SARI) and carefully to review any unusual patterns.

Health care providers are advised to be vigilant for recent travellers who develop severe SARI after returning from areas affected by MERS-CoV, and to obtain specimens from patients’ lower respiratory tracts for diagnosis when possible. Clinicians are reminded that MERS–CoV infection should be considered, even with atypical signs and symptoms, in patients with significantly compromised immune systems.

All Member States are reminded to promptly assess and notify WHO of any new case of infection with MERS–CoV, along with information about potential exposures that may have resulted in infection and a description of the clinical course.

WHO does not advise special screening at points of entry with regard to this event, or recommend the application of any travel or trade restrictions at present.