What is the issue?
This CHO Advisory is an update to the CHO Alert dated 13 January 2014 for Middle East Respiratory Syndrome Coronavirus (MERS-CoV).
Coronaviruses are a diverse family of viruses that include viruses known to cause illness in humans (including the common cold) and animals. Camels are suspected to be the primary source of infection for MERS-CoV in humans, but the exact routes of direct or indirect exposure are not fully understood. It is genetically distinct from the SARS (Severe Acute Respiratory Syndrome) coronavirus, and appears to behave differently.
MERS-CoV was first diagnosed in Saudi Arabia in 2012 where there have been sporadic cases but no evidence of local transmission outside of healthcare settings. Until recently the outbreak had been generally limited to the Middle East, with sporadic cases elsewhere but no ongoing transmission. Since 20 May 2015, there has been an outbreak of MERS-CoV in the Republic of South Korea, the largest reported outbreak to date outside of the Middle East.
As of 16 June 2015, the World Health (WHO) global case count was 1,321 laboratory-confirmed cases of MERS-CoV, including at least 466 known deaths (case fatality rate 35%) since the first case was reported in September 2012.
What is the current situation?
- As of 17 June, a cluster of 162 MERS-CoV cases, including 19 deaths, in the Republic of South Korea (ROK) began with an index case that travelled to multiple countries in the Middle East during the 14 days prior to onset of illness. To date, all other cases have been linked directly or indirectly to the index case, with most transmission occurring in healthcare settings.
- One of the confirmed cases with an exposure history in ROK travelled to Guangdong, China, and on 29 May, China informed WHO that the patient, who was isolated at a Huizhou hospital had tested positive for MERS-CoV.
- Most confirmed cases have presented with, or later developed, acute, serious lower respiratory tract disease. A small number of asymptomatic cases and cases with mild symptoms have been identified through contact tracing.
- Transmission in healthcare settings is the main issue in this outbreak. There is no evidence of ongoing community transmission in ROK, and only occasional instances of household transmission.
- Though data are preliminary, exposure times that led to infection may have been as short as five minutes to a few hours. Given the number of clinics and hospitals that cared for the index case, further cases can be expected.
- Preliminary analysis of full genome sequencing of coronaviruses from the current outbreak does not suggest a more transmissible virus emerging from ROK.
- More information on the current situation is available at the Commonwealth Department of Health .
Who is at risk?
Individuals with a history of travel to, or residence in, the Middle East, or other countries where outbreaks are occurring (currently the Republic of South Korea) in the 14 days before illness onset, and individuals with pneumonia or pneumonitis and history of contact with ccases in the 14 days before illness onset. A list of specific countries where MERS-CoV may be circulating is listed under the ‘Testing’ section.
Nearly half of all confirmed cases have occurred in healthcare-associated clusters, and there have been a number of cases in health-care workers.
Although the exact source of the virus and the mechanism of transmission is unknown, advice for travellers to countries where an outbreak is occurring is to:
- Avoid close contact with people suffering from acute respiratory infections.
- Wash hands frequently (particularly around animals), and practice good respiratory hygiene (cough etiquette etc.)
- Adhere to food safety and hygiene rules – avoid undercooked meats, raw fruits and vegetables (unless peeled), and ensure safe drinking water is consumed.
- Avoid close contact with live farm or wild animals including camels, avoid drinking raw camel milk or eating meat that has not been properly cooked.
Symptoms and transmission
MERS-CoV can range in severity from asymptomatic disease, to mild respiratory symptoms, to severe acute respiratory disease and death. Typical symptoms have included fever, cough, shortness of breath, and breathing difficulties. Pneumonia has been reported commonly, and gastrointestinal symptoms including diarrhoea have been reported. Respiratory failure can occur with severe illness, requiring ventilatory support. Older patients and those who are immunocompromised or have chronic diseases (such as diabetes, chronic lung disease or cancer) appear to be at greater risk of severe disease.
The particular conditions or procedures that lead to transmission in hospital settings have not yet been determined. Infection control recommendations for probable and confirmed cases aim to provide the highest level of protection for health care workers, given the current state of knowledge. Health care workers should follow the NHMRC’s Australian Guidelines for the Prevention and Control of Infection in Healthcare , particularly section B2.4.
Testing should be considered for:
- Individuals with pneumonia or pneumonitis and history of travel to, or residence in, the Middle East, or Republic of South Korea, in the 14 days before illness onset.
- Transiting through an international airport (<24 hours stay, remaining within the airport) in the Middle East is not considered to be a risk factor for infection.
- Countries affected in the Middle East and immediate surrounding areas are Bahrain, Iraq, Iran, Israel, Jordan, Kuwait, Lebanon, Oman, Palestinian territories, Qatar, Saudi Arabia, Syria, the United Arab Emirates (UAE), and Yemen.
- Individuals with pneumonia or pneumonitis and history of contact with those in point 1 above in the 14 days before illness onset.
- Health care workers with pneumonia, who have been caring for patients with severe acute respiratory infections, particularly patients requiring intensive care, without regard to place of residence or history of travel, where another cause has not been confirmed.
Clinicians should be alert to the possibility of atypical non-respiratory presentations in immunocompromised patients, but testing for MERS-CoV should be performed in patients with radiological evidence of pneumonitis with the appropriate travel/contact history.
How to test for MERS-CoV
- Testing should only be carried out after discussion with the Communicable Disease Prevention and Control Section at the Department of Health and only where MERS-CoV is suspected on clinical and epidemiological grounds.
- All testing for MERS-CoV in Victoria will be carried out at the Victorian Infectious Diseases Laboratory (VIDRL), and only after authorisation by the Department.
- Transmission-based contact and airborne precautions must be used when taking respiratory specimens. These are described in NHMRC: Australian Guidelines for the Prevention and Control of Infection in Healthcare – 2010 (particularly section B2.4), and include the requirement for negative pressure air-handling and PPE including the use of gloves, gowns, P2 (N95) respirators, eye protection and hand hygiene.
- Routine tests for acute pneumonia should be performed where indicated, including bacterial culture, serology, urinary antigen testing and tests for respiratory viruses.
- Respiratory samples including upper respiratory tract viral swabs, nasopharyngeal aspirates, sputum, bronchoalveolar lavage fluid, lung biopsies and post-mortem tissues are suitable for testing for MERS-CoV. Lower respiratory tract specimens should be collected where possible.
- The WHO emphasises repeat testing (especially of lower respiratory tract specimens) in compatible cases as initial results may be negative.
- Laboratory staff should handle specimens under PC2 conditions in accordance with AS/NZS 2243.3:2010 Safety in Laboratories Part 3: Microbiological Safety and Containment.
- The Communicable Disease Prevention and Control Section will authorise testing and advise VIDRL to expect the samples, which should be transported in accordance with current regulatory requirements.
In patients with pneumonia or pneumonitis with travel to affected countries in the Middle East or the Republic of South Korea, or contact with known confirmed or probable cases within two weeks of illness onset, the following is recommended:
- Place the patient in a single room with negative pressure air-handling, and implement transmission-based precautions (contact and airborne) as per NHMRC , including the use of personal protective equipment (PPE).
- Investigations and management should be performed as for community acquired pneumonia. Appropriate specimens should also be collected for MERS-CoV PCR testing.
- If transfer of a suspected, probable or confirmed case outside the negative pressure room is necessary, ask the patient to wear a single use face mask (i.e. surgical face mask) while they are being transferred and to follow respiratory hygiene and cough etiquette.
- Notify the Department of Health and Human Services on 1300 651 160 of any suspected (and probable or confirmed) cases in order to discuss and co-ordinate testing and management of contacts.