Middle Eastern respiratory syndrome coronavirus mers cov infection and precautions for Australia

13 Dec Middle Eastern respiratory syndrome coronavirus mers cov infection and precautions for Australia

MERS-CoV infection has been diagnosed in over 1,300 cases worldwide, with 85% of cases recorded in Saudi Arabia. The Middle Eastern cases have been associated with a very high fatality rate of some 40%. Since the first cases of MERS were noted, a small number of cases have been recognised in other countries, mostly in the Middle East, but also in other countries such as France, UK and the Philippines. All have been exported from the Middle East or can be linked to infection acquired in Saudi Arabia. There has not been any sustained transmission from these cases previously. In the last two weeks, an outbreak has occurred in South Korea (RoK) following introduction of the virus by a traveller returning from Saudi Arabia. Sustained person-to-person transmission has continued since then, almost exclusively in health care settings. Updated information on MERS epidemiology and clinical features is available from the Commonwealth’s Department of Health wesbite and fact sheet, or at this link.

The first Korean case was not diagnosed until nine days after initial presentation, and by that time, the patient had visited six hospitals as well as other health clinics. There have now been more than 160 cases recorded in RoK. As at Tuesday, 16 June 2015, 18 deaths had occurred, 13 patients were being ventilated for respiratory failure and three more were receiving extra-corporeal membrane oxygenation. All but one of the Korean cases is linked to the original patient in the chain of transmission. Several thousand potential contacts of these cases are now under home quarantine in Korea.

The growing experience with MERS-CoV infection suggests that the clinical features of infection can vary widely and that pneumonia is less frequent than previously thought, especially at the time of initial presentation (18%). A wide range of respiratory and other features including gastrointestinal symptoms have been noted with similar or higher frequency.

Epidemiological analysis of the RoK outbreak has provided several key insights:

* MERS was unsuspected by and unfamiliar to the Korean doctors and health personnel
* Prevention and control measures in health care settings were ineffective and insufficient
* Overcrowding in clinics and wards and “doctor shopping” contributed to the spread of infection to other centres and within centres
Professor Baggoley has noted that “in alert and well functioning health systems, the risk of transmission is low”. He has emphasised the need to ask about travel to the Middle East in the last 14 days in all patients presenting with respiratory or influenza-like symptoms, and stressed the importance of keeping the data on non-specific features of the presenting illness in mind.

Specific Australian infection prevention and control guidelines will be released via the Department website in the very near future. These will be concise and in a familiar format, and will focus on standard contact and airborne droplet precautions. Clinicians are reminded of the need to contact Public Health Units as soon as possible in the event that a possible case is identified (after isolation of the patient to the greatest extent possible in the situation), and of the need to ensure that other relevant services such as labs, Infectious Diseases Units, and Infection Control teams are notified in hospital settings. The guidelines will provide specific instructions on the safe collection and handling of optimal diagnostic specimens, but will have a distinct emphasis on meticulous technique, especially the use of carefully fitted P2 level (N95) masks. Guidelines promulgated by the US Centers for Disease Control and Prevention are readily available and are very largely consistent with the forthcoming Australian ones.

In Australia the recommendation is that we need to be alert and ensure that the appropriate information is sought as part of the medical history in any relevant setting, however this will be difficult with the current influenza season currently underway. In addition the annual season for pilgrimages to Mecca will commence in September and that travel to and from Saudi Arabia will increase greatly as a result. There have been no cases of MERS recorded in returning pilgrims anywhere to date, but appropriate vigilance should be maintained.

Source: The Royal Australian College of Physicians