MERS is name of the illness caused by the coronovirus, MERS-coV. Because it's a virus and not a bacteria, there is no specific medicine or antibiotic to use against it.
It's also not a superbug. Superbugs are bacteria-based organisms, such as the similarly named MRSA, which have become resistant to the antibiotics used to treat patients.
But one thing MERS is—it's new. It was first reported in Saudi Arabia in 2012. In fact it takes its name from ts region of origin, the Middle East. That's also where the majority of cases have been documented. So far, every reported case of MERS worldwide has been linked to countries in the Arabian Peninsula.
The CDC says it doesn't know exactly where the virus originated, but the likely source is an animal species—specifically, camels.
People affected by the MERS virus develop a severe acute respiratory illness, with symptoms including fever, cough, and shortness of breath. The virus has a current fatality rate of 30 percent, according to the CDC. What medical professionals do is react to the symptoms to control the virus.
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The real trouble with MERS may be how easily it spreads. The virus can go from person to person who are in close contact with each other, and that includes transmission from infected patients to health-care workers in hospitals.
The two MERS patients in the U.S. are health care providers who were working in Saudi Arabia.
Experts do not yet know precisely how the virus is spread—whether it's by coughing, or sneezing or simply touching someone.
"We just don't know enough yet on how it's being passed from person to person," said CDC spokesman Jason McDonald in a phone call with CNBC.
However, the CDC advises people to help protect themselves from respiratory illnesses by washing their hands often, avoiding close contact with people who are sick, avoiding touching their own eyes, nose or mouth with unwashed hands, and disinfecting frequently-touched surfaces.