MERS Upsurge: Mutation or surveillance artifact?

March 18th, 2015

As MERS infections have dramatically increased in the Middle East, concerns have mounted that the novel coronavirus has mutated, much as its SARS predecessor did.

“The fact that 200 new cases were reported by Saudi Arabia and the United Arab Emirates in the single month of April 2014 has raised concerns that viral mutations have led to enhanced adaptation to human hosts,” says Stan Deresinski, MD, FACP, FIDSA, an infectious disease physician and professor of medicine at Stanford University. “The available evidence, however, has not, to date, confirmed this fear. Rather, it has been suggested that at least part of the reason has been increased recognition of the disease.”(1)

Another suspected factor in the upsurge of cases is the mass birthing of dromedary camels (the one-humped type) that occurs every winter in breeding facilities, he explains.

The virus, like the SARS coronavirus, has been found in bats. Their role is uncertain, but dromedary camels are an important reservoir of the MERS virus. For example, a country-wide survey in Oman led to its detection in camel conjunctival and nasal secretions. The camel viruses were closely related to MERS of human origin detected in the same geographic area.(2)

“In a few cases, closely related MERS-CoV has been identified in humans and camels with which they have had contact,” Deresinski says.

Thus, it has been suggested that human infections may result from contact with the animals, eating camel meat, and the common practice of consuming unpasteurized camel milk may represent important means by which humans become infected, he notes.

References

1. Kupferschmidt K. Soaring MERS Cases in Saudi Arabia Raise Alarms. Science. 2014; 344:457-458.

2. Nowotny N, et al. Middle East respiratory syndrome coronavirus (MERS-CoV) in dromedary camels, Oman, 2013. Eurosurveillance, 2014;19:24