Middle East Respiratory Syndrome, or MERS, has infected more than 500 people since it was first identified in 2012. About 30 percent of those who contract it die. The steep increase in the number of cases in recent months, and the fact that people in Asia, Europe and North America have come down with the virus, have raised concern that the situation may worsen.
The last pandemic occurred in 2009, with the H1N1 influenza virus. The World Health Organization says MERS is a long way from becoming a pandemic. Most cases have been in Saudi Arabia, among people with close contact with MERS patients or with camels that carry the virus.
However, a virus can change at any time, so officials like Dr. LaMar Hasbrouck, who heads the Illinois department of public health, say there is need for concern.
Countries reporting new MERS cases, 2014, May 13 update
"It's a new virus. It has a very high death rate, but we need to learn more about how easily it's transmitted, and what are some of the signs and symptoms," said Hasbrouck.
Many hospitals already have plans to prevent the virus from spreading. At The Johns Hopkins Hospital in Baltimore, it's Dr. Gabe Kelen's responsibility to ensure the plan covers all of the 46,000 people at the clinics and medical centers, as well as the university.
“I’m not that concerned yet, however, for our level of preparation; we want to stay ahead of the curve. That should this happen; we’re not playing catch-up," said Kelen.
This is not just for MERS, but for any contagious disease.
"When anyone comes into the emergency department with an influenza-like illness, we already have a protocol to screen them and to test them and if we believe they may have a serious infection, they get isolated, they get a mask. Anyone who goes in after to deal with that patient has certain precautions," he said.
Doctors, nurses, even the cleaning staff, might have to wear gowns, gloves and special masks.
During the H1N1 influenza pandemic, hospitals set up special clinics, some in tents outside the building, to diagnose patients suspected of having the flu. This practice could be reinstated to prevent the spread of a virus, and lower the chance it could mutate into something even more deadly.
“The more often it [a virus] gets transmitted, the more the virus replicates. The more the virus replicates and in different hosts, the more likely its genetic makeup may change," said Kelen.
After the outbreak of severe acute respiratory syndrome, or SARS, more than a decade ago, the world learned that an infectious disease anywhere is a health challenge everywhere, largely because of air travel. Countries learned they had to share information about diseases in order to control them.
Later this year, Saudi Arabia will host millions of religious pilgrims. Health officials the world over will be carefully watching.