MERS 'Super-Spreaders' Pose Threat to HCWs, Patients

July 12th, 2016

By Gary Evans, Senior Staff Writer, AHC Media

The quasi-medical term “super-spreader” has been coined to describe a single person who infects an unusually large number of contacts.

The concept goes back at least to “Typhoid Mary,” but was popularized during the 2003 SARS outbreak in Canada. With SARS -- and a similar, currently emerging coronavirius, -- Middle East Respiratory Syndrome (MERS), health care workers seem particularly vulnerable to the super-spreader phenomenon.

For example, the World Health Organization is investigating a recent MERS outbreak in a hospital in Saudi Arabia where a single patient infected 24 contacts – 11 of them healthcare workers. Similarly, researchers recently reported explosive spread of MERS from a single patient in a Korean emergency room that included eight healthcare workers.

The outbreak of MERS occurred in the Samsung Medical Center, in Seoul in 2015. In a recently published analysis of exposure and transmission the researchers found that the patient – who would appear to meet the general definition of a super-spreader – exposed 218 health-care workers and hundreds of patients and visitors while in emergency room between May 27 and May 29.

MERS infection was confirmed in eight healthcare workers, 33 patients and 41 visitors.

“Our results showed increased transmission potential of MERS from a single patient in an overcrowded emergency room and provide compelling evidence that health-care facilities worldwide need to be prepared for emerging infectious diseases,” the authors concluded.

Neither of these index patients was initially suspected of having MERS, thus the full rigor of infection control precautions may have been lacking.

MERs was stopped quickly in the U.S. in 2014 when two unrelated cases were admitted to hospitals in Indiana and Florida. Those cases involved healthcare workers who had recently worked in Saudi Arabian hospitals, but next time MERS may not be so obviously identified. Crowded U.S. emergency rooms could certainly be vulnerable to an undiagnosed MERS patient.

Globally since September 2012 the WHO has been notified of more than 1,700 laboratory-confirmed cases of infection with MERS, in 27 countries, including more than 600 deaths.