Middle East Respiratory Syndrome (MERS)

Primary reference(s)

WHO, 2019. Middle East respiratory syndrome corona (MERS-CoV). World Health Organization (WHO). Accessed 13 December 2019.

Additional scientific description

Middle East respiratory syndrome (MERS) is a zoonotic disease that can be transmitted between animals and people mostly in countries in the Middle East (WHO, 2019), however, an importation of MERS-CoV into the Republic of Korea in 2015 led to the largest MERS outbreak outside of the Middle East.

Since 2012, 27 countries have reported cases of MERS globally and 12 of them are located in the Eastern Mediterranean Region. Approximately 80% of human cases have been reported by Saudi Arabia (WHO, 2019).

A typical presentation of MERS-CoV disease is fever, cough and shortness of breath. Pneumonia is a common finding. Gastrointestinal symptoms, including diarrhoea, have also been reported. Severe illness can cause respiratory failure. The case fatality rate of MERS is been estimated around 35% (WHO, 2019).

Diagnosis is made with clinical, radiological, or histopathological evidence of pulmonary disease and also related to other confirmed cases and any history of residence or travel in countries where MERS-CoV is known to be circulating (WHO, 2019).

No vaccine or specific treatment is currently available, however several MERS-CoV specific vaccines and treatments are in development. Treatment is supportive and based on the patient’s clinical condition.

The World Health Organization (WHO) has published guidance on case classification and surveillance standards (WHO, 2017).

Metrics and numeric limits

Not applicable.

Examples of drivers, outcomes and risk management

Current scientific evidence suggests that camels are a major reservoir host for MERS-CoV and an animal source of MERS infection in humans (WHO, 2019).

Anyone visiting farms, markets, barns, or other places where dromedary camels and other animals are present should practice general hygiene measures, including regular hand washing before and after touching animals, and should avoid contact with sick animals (WHO, 2019).

Appropriately processing animal products through cooking or pasteurisation or handling to avoid cross-contamination is also essential (WHO, 2019).

Although most human cases of MERS-CoV infections have been attributed to human-to-human infections due to close contact in health care settings of patients, healthcare workers or among family members, human-to-human transmission has been limited to date. About 20% of MERS cases occurred in healthcare workers so infection prevention and control measures are critical to prevent the possible spread of MERS‐CoV in healthcare facilities. Healthcare associated outbreaks have occurred in several countries, with the largest outbreaks seen in Saudi Arabia, United Arab Emirates, and the Republic of Korea (WHO, 2019).