The second American case of the MERS virus has been reported in Florida, according to NBC News. The case seems to be unrelated to the first US case of the virus, which struck a health-care worker in Munster, Indiana, but has many officials concerned about MERS' potential to spread globally. MERS was first identified in 2012, but this March saw a surge in cases for reasons that remain unclear. Since then, there have been a total of 538 laboratory-confirmed cases of the virus globally, 450 of which have been in Saudi Arabia. In roughly one-third of infections, the virus proves fatal.

"Unwelcome but not unexpected news."

CDC Director Tom Frieden described the latest case as "unwelcome but not unexpected news." The patient had traveled from Jeddah, Saudi Arabia on May 1st, stopping through London, Boston and Atlanta before arriving in Orlando, Florida, where he was hospitalized. While the patient was symptomatic during the flights, researchers emphasize that there is no evidence yet that he was infectious. According to the CDC, his current condition is "stable and doing well."

"Infection control is really critical."

The hospital is using airborne isolation tactics, as recommended by the CDC, but Frieden emphasized that "our experience with MERS suggests that the risk to the general public is very low." Researchers say the virus does not spread easily from person-to-person, typically spreading only through close contact, usually through living with or caring for an infected person. At the same time, once a person does become infected, doctors face limited treatment options. "This is not a virus we can treat with specific antivirals right now," Assistant Surgeon General Anne Schuchat told reporters, "so infection control is really critical."

At the same time, the Indiana case appears to be winding down. The Washington Post reports that the patient has made a full recovery, and the case seems to have been entirely contained. The CDC investigation is "relatively complete," and hasn't turned up any secondary cases. Even more important to epidemiologists, genetic testing of the virus suggests that it has not changed much from earlier samples, indicating that its behavior should remain fairly predictable.

Update 2:30pm EST: Updated to include information from the CDC.