In the News: Second MERS Case Diagnosed in U.S.

By: Amesh A. Adalja, M.D., FACP, FACEP

The announcement today of a second U.S. case of the Middle East Respiratory Syndrome (MERS) in a healthcare worker who had traveled to Florida from the Middle East has caused understandable worry given its many similarities with the 2003 pandemic of Severe Acute Respiratory Syndrome (SARS).

MERS is an acute respiratory illness that has been smoldering in the Middle East region of the globe accruing more than 500 cases since 2012.  Most worrisome is that the disease—for which there is no vaccine or specific treatment—has the ability to cause severe illness with fatality rates of 36 percent. MERS has also exploited lapses in hospital infection control practice to spread within healthcare facilities. The fact that both U.S. cases were healthcare workers who contracted the illness while working in Saudi Arabia is no accident.

Amesh Adalja

Amesh Adalja

One difference with SARS is that much of the spread of SARS was attributed to the existence of superspreaders, individuals who disproportionately shed the virus in excessive amounts. Fortunately, no MERS superspreaders have been identified to date.

MERS represents yet another example of an emerging virus spilling from an animal population into humans. In this case, it is hypothesized that camels may have contracted this virus from bats and are now spreading it among human populations.

Earlier this month, the first domestic MERS case was discovered in Munster, Indiana, in a healthcare worker who traveled from Saudi Arabia. His travel was not thought to pose a risk to fellow travelers although passengers that flew with him were contacted. Fortunately, his case was mild and did not require ICU level care. He has since left the hospital.

The second case, which is not connected to the first domestic case, is also related to travel from Saudi Arabia.

Domestic cases of MERS are not to be unexpected as this virus has already made appearances in the United Kingdom, Italy and France. The world is a small place and an infection on one side of the planet can easily appear on the other side. In fact, during SARS eight U.S. cases occurred, including one in Pennsylvania. More importations are anticipated.

Members of the general public need not panic as this virus does not pose a threat to them. However, if one has traveled to the Middle East (in the last 3 weeks) or been in contact with those who have traveled to the region and are experiencing fever and upper respiratory symptoms they should contact their physician.

The detection of this case represents proof of the concept that astute clinicians, aware of a patient’s travel history, in possession of the knowledge of infectious disease outbreaks worldwide, and given the ability to confirm cases are able to detect novel infectious diseases and hopefully mitigate their consequences.

For more information on MERS, check out Dr. Adalja’s blog Tracking Zebra.