Middle East respiratory syndrome coronavirus

Human coronaviruses are a group of viruses that cause respiratory infections in humans and animals.

Coronaviruses can cause a range of symptoms varying from mild symptoms such as the common cold to more serious respiratory illnesses.¹ This particular coronavirus was initially called novel coronavirus but is now called Middle East respiratory syndrome coronavirus (MERS-CoV). It was first identified in September 2012 in a patient who had died from a severe respiratory infection in June 2012. Following this there have been cases reported in the Middle East and UK with the threat of infection spreading throughout the world. See the World Health Organization (WHO) website for the latest updates. Always take a detailed history from any person who is unwell and has returned from abroad.

Transfer from camels to humans has been reported.² Human-to-human transmission is possible between close contacts, particularly in clinical settings, but is rare outside of healthcare settings.³

Middle East respiratory syndrome (epidemiology)

The incubation period is currently considered to be up to ten days and therefore any respiratory illness occurring in the ten days following last contact with a confirmed person with MERS-CoV is considered relevant and close contacts should self-isolate and alert their GP as soon as possible.

MERS has presented so far as an acute, serious respiratory illness with fever, cough, shortness of breath, and breathing difficulties. There was a significant mortality (greater than 50%) for the confirmed cases in the first six months of virus identification. Current statistics suggest that the mortality rate is around 35% but it is thought that this is an overestimate as milder cases are more likely to be unreported or unrecognised.³ Patients with MERS-CoV are thought to be asymptomatic or have very mild symptoms in between 25 and 50% of cases.⁴

80% of cases have been reported in Saudi Arabia, mostly as a result of transmission from infected camels or from healthcare settings. Cases outside of the Middle East appear to have occurred in people who have recently travelled there.³

Middle East respiratory syndrome symptoms (presentation)¹

Travellers returning from the Arabian peninsula and surrounding countries with significant respiratory symptoms such as shortness of breath should be assessed for the possibility of MERS-CoV infection.

Primary care healthcare workers should consider MERS-CoV in any person with:

• Symptoms of fever (≥38°C); AND

• History of cough and/or breathlessness or clinical signs of lower respiratory tract infection; OR

• Other severe/life-threatening illness suggestive of an infectious process.

AND EITHER

• History of travel to, or residence in an area where infection with MERS-CoV could have been acquired (currently Bahrain, Iran, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, United Arab Emirates and Yemen), but check the Health Protection Agency (HPA) and WHO websites for updates) within two weeks of symptom onset; OR

• Close contact during the 14 days before onset of illness with a confirmed case of MERS-CoV infection while the case was symptomatic; OR

• A healthcare worker based in ICU caring for patients with severe acute respiratory infection, regardless of history of travel or use of personal protective equipment (PPE) - full PPE is correctly fitted high-filtration respirator, gown, gloves and eye protection); OR

• Part of a cluster of two or more epidemiologically linked cases within a two-week period requiring ICU admission, regardless of history of travel.

Close contact is defined as:

• Prolonged face-to-face contact (>15 minutes) with a symptomatic confirmed case in a household or other closed setting; OR

• A healthcare or social care worker who provided direct clinical or personal care or examination of a symptomatic confirmed case, or within close vicinity of an aerosol-generating procedure AND who was not wearing full PPE at the time.

Investigations⁵

For suspected cases and close contacts, primary care health workers should follow the algorithm suggested by UK Health Security Agency. Initially, the health protection team and duty microbiologist/virologist at the local public health laboratory should be contacted. A clinical risk assessment should be performed by a local clinical microbiologist. Full PPE should be worn.

Middle East respiratory syndrome treatment and management⁶

• The role of primary care health workers is limited, as described above.

• Secondary care clinicians should manage the patient using standard transmission-based precautions for respiratory tract infections.

• Full PPE is essential for all those in close contact with the patient.

• There is no specific treatment. Management of severe infections is the same as for any cause of acute respiratory distress syndrome.

• Any patient with severe symptoms will require admission to hospital and management within an ICU.

Prevention

There is currently no vaccination available for protection. Anyone travelling to the Middle East or any other country considered to be a risk for becoming infected with MERS-CoV should check the National Travel Health Network and Centre (NaTHNaC) website.⁷

Healthcare workers should ensure they wear full protective equipment when caring for people with suspected MERS-CoV infection.

Camel owners should maintain impeccable personal hygiene measures after handling camels and ensure that any camels that are unwell (eg, rhinitis, conjunctivitis) should be kept away from the general public. Members of the public visiting farms or other places where they may have contact with camels should ensure scrupulous handwashing.³ It is also recommended to avoid raw camel milk or camel products from the Middle East, as well as avoiding any other raw milk products or other food contaminated with animal secretions, unless it has been thoroughly cleaned or peeled and cooked.