Middle East Respiratory Syndrome (MERS) is a viral respiratory infection caused by a novel strain of coronavirus first identified in September 2012 and called MERS coronavirus (MERS-CoV). MERS-CoV is genetically distinct from the coronavirus that caused the SARS outbreak. To date, all cases have either occurred in the Middle East, have
had direct links to a primary case infected in the Middle East or have returned from the Middle East.
Update - 28 November 2013:
Between 19 and 25 November 2013, three additional cases were reported to WHO by the local health authorities from Saudi Arabia. Confirmatory testing continues for two probable case reported by Spain in returned travellers from the Hajj in Saudi Arabia. Globally to date, WHO report that there have been a total of 160 laboratory-confirmed cases of infection with MERS-CoV, including 68 deaths.
The WHO MERS-CoV Research Group has recently published a comprehensive review on MERS-CoV in PLOS.
WHO does not recommend the application of any travel restrictions to affected countries but have provided travel advice for people making pilgrimages in Saudi Arabia.
The NSW Health Hajj Travel Advice factsheet also has health information for pilgrims travelling to Saudi Arabia to perform the Hajj and Umrah.
Health Professionals advice