Middle East respiratory syndrome (MERS) is a viral respiratory disease caused by a novel coronavirus that was first identified in Saudi Arabia in 2012. Coronaviruses are a large family of viruses which include viruses that may cause mild illness like common cold as well as severe illness like severe acute respiratory syndrome (SARS) in humans. There are 3 main subgroups of coronaviruses: alpha (α), beta (β) and gamma (γ). Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a beta coronavirus which has not been identified in humans before and is different from other coronaviruses (including SARS-coronavirus) that have been found in humans or animals.
Infected persons may present with acute serious respiratory illness with symptoms including fever, cough, shortness of breath and breathing difficulties. Patients with MERS may develop severe complications such as pneumonia and kidney failure. Some also have gastrointestinal symptoms including diarrhoea and nausea/vomiting. In people with immune deficiencies, the disease may have atypical presentation. Some laboratory-confirmed cases of MERS-CoV infection are reported as asymptomatic. Approximately 35% of reported MERS patients died.
Mode of transmission
There is still uncertainty at the moment. People may be infected upon exposure to animals (especially camel), environment or other confirmed patients (such as in a hospital setting).
Based on the current information, MERS-CoV could be spread from person-to-person through close contact. Since April 2014, many cases appeared to be secondary cases which might have been infected from a confirmed patient. These secondary cases were mainly healthcare workers who were in close contact with or providing unprotected care to patients with MERS-CoV infection and were infected within healthcare settings.
Besides, scientific studies support that dromedary camels serve as a major reservoir host for MERS-CoV and an animal source of infection in humans.
2 – 14 days
There is currently no specific treatment for the disease. Treatment is supportive.
No vaccine is currently available to protect against MERS. The best preventive measure is to maintain good personal and environmental hygiene. While in Hong Kong or during travel, members of the public are advised to wear surgical mask and seek medical advice promptly if respiratory symptoms develop.
1. Maintain good personal hygiene
2. Maintain good environmental hygiene
Though coronaviruses may survive for some time in the environment, they are easily destroyed by most detergents and cleaning agents. It is important to:
Travel health advice
Consult a health care provider at least 6 weeks before travelling to review the risk, as pre-existing major medical conditions including diabetes, chronic lung disease, pre-existing renal failure, or immunocompromised conditions can increase the likelihood of medical problems, including MERS, during travel.
Special note for people planning to travel for pilgrimage
Pilgrims with pre-existing major medical conditions (e.g. diabetes, chronic lung disease, chronic renal disease, immunodeficiency, etc.) are more likely to develop severe infection for MERS if they are exposed to the virus. Thus, pilgrims should consult a health care provider before travelling to review the risk and assess whether making the pilgrimage is advisable. They are advised to delay travel if suffering from a significant acute respiratory illness with fever and cough.
Pilgrims should cover their mouth and nose when coughing or sneezing, and wash hands after contact with respiratory secretions. If suffering from acute febrile respiratory symptoms, keep a distance of one metre with other persons.
If pilgrims develop a significant acute respiratory illness with fever and cough (severe enough to interfere with usual daily activities) during Umra or Hajj, they should:
If pilgrims feel unwell during the two weeks after returning to Hong Kong, wear a surgical mask and seek medical attention immediately and inform doctor of recent travel history, including transit.
For details, please refer to the thematic webpage of Middle East Respiratory Syndrome.