Since September 2012, in 26 countries around the world, there have been 1,348 laboratory-confirmed cases of infection with Middle East Respiratory Syndrome (MERS), including at least 479 related deaths. Most recently, ongoing cases have been reported in the Republic of Korea.
MERS is a viral respiratory illness caused by the coronavirus MERS-CoV. Current evidence suggests that MERS does not pose a risk of transmission through plasma-derived products, such as clotting factor concentrates. Lipid-enveloped RNA viruses, such as the coronavirus, should be removed or inactivated during the manufacturing of plasma derivatives through intentional viral clearance procedures. These procedures, including filtration, heating, pasteurization, acidification, and detergent treatment, are validated to be effective against lipid-enveloped RNA viruses. MERS-CoV is not the same coronavirus that caused severe acute respiratory syndrome (SARS) in 2003. However, like the SARS virus, MERS-CoV is most similar to coronaviruses found in bats.
MERS-CoV, like other coronaviruses, is thought to spread from an infected person’s respiratory secretions, such as through coughing. The precise mechanism of transmission is still not well understood. MERS-CoV has spread from sick people to others through close contact, and infected people have spread MERS-CoV to others in healthcare settings. Currently, there is no vaccine available to protect against MERS.
At this time, all reported cases have been linked to countries in or near the Arabian Peninsula. Most infected people either lived in the Arabian Peninsula or recently traveled from there before they became sick. Some people have been infected with MERS-CoV after close contact with an infected person who had recently traveled from one of the affected countries. Public health agencies are continuing to investigate clusters of cases in several countries to better understand how MERS-CoV spreads from person to person.
The European Centers for Disease Control has stated “The absence of reported transmission through blood transfusion or transplantation and experience with related SARS coronavirus viraemia, which seemed largely confined to the symptomatic patients, suggest that the current risk of donor-derived MERS-CoV transmission is very low. Thus specific deferrals of donors returning from affected countries are not considered necessary at this stage of the outbreak. Safety criteria for prospective donors presenting with acute respiratory symptoms are sufficient to identify symptomatic MERS-CoV cases residing in or returning from affected countries and exclude them from the donation of blood, cells and tissues, and organs.”
The WFH will continue to monitor the MERS outbreak. MERS updates can be found at: