(NaturalNews) A pair of American hospital workers who got sick after coming in contact with a patient suffering from Middle East Respiratory Syndrome, or MERS, have since tested negative for the virus, which can often prove deadly, according to a Florida health official.

Reuters and other news agencies reported that U.S. health officials had only recently confirmed that the nation's first two cases of MERS had been verified, which raised new fears about the potential global spread of the virus.

MERS is responsible for the worst outbreak in Saudi Arabia, though more than 500 cases have been reported around the globe. Thirty percent have been fatal, reports said.

Earlier in May the World Health Organization said that though its concern over MERS had increased quite significantly, the disease is not yet posing a global health crisis.

Reports said that the second patient in the U.S. confirmed to have contracted the disease was hospitalized in Orlando, Florida, following a 12-hour stay in an emergency department, which potentially exposed employees to the virus.

Officials at the Dr. P. Phillips Hospital, where the patient remains, said he was in isolation and as of May 18 had been fever-free for 24 hours.

It is difficult to tell how many are infected

Reuters noted:

Florida officials said they were monitoring a total of 20 healthcare workers who had been in contact with the patient. Test results for 19 of those workers were negative for MERS, according to Kevin Sherin, director of the Florida Department of Health in Orange County. The 20th worker, a doctor who had left for Canada, was still awaiting test results.

Scientists and researchers say they don't have many details about how the virus spreads. Healthcare workers, however, have proven to be particularly vulnerable since they are in close contact with MERS-infected patients. Both U.S. cases involved healthcare workers who had previously spent time in Saudi hospitals treating people with the disease.

Reports said that U.S. officials had posted signs near security and customs checkpoints at primary international airports like Atlanta's Hartsfield Jackson, the Dallas/Fort Worth airport, and New York's John F. Kennedy, informing passengers about MERS and asking them to take precautionary measures like washing hands and reporting any flu-like symptoms.

On its website the Centers for Disease Control and Prevention (CDC) says MERS is a "viral respiratory illness first reported in Saudi Arabia in 2012. It is caused by a coronavirus called MERS-CoV. Most people who have been confirmed to have MERS-CoV infection developed severe acute respiratory illness. They had fever, cough, and shortness of breath."

"So far, all the cases have been linked to countries in the Arabian Peninsula. This virus has spread from ill people to others through close contact, such as caring for or living with an infected person. However, there is no evidence of sustained spreading in community settings," the CDC said.

'We don't know what proportion of people are infected'

The organization issued a "Level 2" alert regarding travel to the Arabian Peninsula and advised travelers to pay close attention to their health during and after their trip. CDC officials have so far not recommended that anyone change their travel plans to the region.

According to a CDC analysis, New York City is expected to see the greatest influx of airline travelers from Saudi Arabia and the United Arab Emirates in May and June this year, at nearly 31,000 people, Reuters reported. Washington, D.C. was second on the list at more than 24,500 passengers, followed by Los Angeles at more than 15,000.

UPDATE:

USA Today reported May 19 that a third MERS case had been confirmed in the U.S.

"We don't know what proportion of infected people are asymptomatic, what proportion of people are symptomatic and what proportion of people have severe disease," said David Swerdlow, incident manager for MERS response activities at Centers for Disease Control and Prevention in Atlanta.

The paper said tests show an Illinois man who had finished up a pair of short business meetings with an infected Indiana man, had contracted the virus.

Sources for this article include:

http://news.yahoo.com

http://www.cdc.gov/CORONAVIRUS/MERS/INDEX.HTML

http://www.usatoday.com