Updated: 28 January 2016
What is MERS-CoV?
A new virus that caused respiratory illness became known to the world in 2012. It was named as "Middle East Respiratory Syndrome Coronavirus" (MERS-CoV) reflecting the geographical area affected.
The source of infection, though not confirmed, is likely through contact with dromedary camels or their raw products. Although cases have been reported in health care settings, human to human transmission has occurred in a limited fashion.
Globally, more than a thousand cases have been confirmed since 2012. Over a third of those who got infected have died. All the cases identified have been linked to countries in the Arabian Peninsula either in residents, travellers, migrants or close contacts of the travellers. Around 65% of cases are males. All age groups have been affected, but most individuals were aged between 40 to 50 years.
Cases have originated in most of the countries on the Arabian Peninsula. (For the full list of countries click here)
Some people who were infected on the Arabian Peninsula travelled to other countries and were diagnosed with MERS-CoV there (imported cases). (For the full list of countries click here)
Risk to individual humans? Risk of a pandemic?
Individuals at risk include;
- People with exposure to dromedary camels or their raw products. How the infection gets transmitted is not yet known, but MERS-CoV has been found in some dromedary camels. Research has shown direct contact with other animals such as goats or sheep or their raw/undercooked products (milk, meat) may also play a part.
- Healthcare workers in contact with confirmed or suspected cases.
- Close contacts of confirmed cases.
- People with a history of recent travel to the Arabian Peninsula and their close contacts.
The risk increases if the individuals have pre-existing co-morbidities (diabetes, kidney failure or chronic lung disease) or weakened immune systems.
Human to human spread
There has been limited human-to-human transmission causing small outbreaks in communities and larger outbreaks in healthcare settings (these are secondary cases). However, WHO has stated ‘there is no evidence of sustained human-to-human transmission in the community.’ Moreover, the secondary infections are milder than those seen in primary cases. The rise in secondary cases in 2015 is attributed mainly to inadequate infection control measures in hospitals.
Any of the following scenarios could occur with MERS-CoV:
- It could continue to be localised to the Middle East with sporadic export of cases to other countries.
- Detection of primary cases in countries outside Middle East.
- Slow or stop – source of the virus identified and its transmission to humans reduced or stopped.
- Become more adapted to humans and able to transmit easily from person to person (could cause a regional epidemic or if it spreads to other continents, could become a pandemic).
Snapshot of global MERS-CoV activity
Countries affected in 2015 in the Middle East - Saudi Arabia, Iran, Jordan, Oman, Qatar and United Arab Emirates.
Countries affected in 2015 in other parts of the world – China, Germany, Philippines, South Korea and Thailand.