WASHINGTON -- A health care worker from Saudi Arabia is hospitalized in Orlando, Fla., with the second confirmed U.S. case of the deadly Middle East Respiratory Syndrome, or MERS, government officials reported Monday.
Health officials from 20 states are notifying more than 500 U.S. passengers who were on May 1 flights with the infected patient that they might have been exposed to the disease. The travelers are being told that if they develop coldlike symptoms, they should contact health care providers, get tested for possible exposure to the disease and take precautions to limit their contact with others.
"For the traveling public, I'd like to reassure them that it is likely that if you haven't already developed symptoms, you're probably not going to," said Anne Schuchat, director of the National Center for Immunization and Respiratory Diseases at the U.S. Centers for Disease Control and Prevention.
Since the incubation period for MERS is about five to 14 days, "we are getting toward the end of the period where we think it would be biologically possible for them to acquire infection," Dr. Schuchat said in a call with reporters. More than 150 passengers already have been found to have no trace of the virus, officials said Monday.
The new MERS case is not linked to the first U.S. case, which was confirmed last week in Indiana.
A viral respiratory illness, MERS was first discovered in Saudi Arabia in 2012. Since then, 538 people have contracted the disease, and 145 have died. Saudi Arabia's 450 confirmed cases and 118 MERS deaths lead the world.
Officials maintain that the health risk to the greater U.S. public remains "very low," since spread of the virus requires close contact with an infected person.
"This virus has not shown the ability to spread easily from person to person in community settings," Dr. Schuchat said. "Clusters of human-to-human spread have been seen most frequently in health care workers who have been caring for MERS patients."
In fact, health care workers make up about 20 percent of all confirmed MERS cases, she said.
The unnamed Florida patient, who also worked at a Saudi facility that treats MERS patients, became ill during a May 1 flight from the Middle East to London and on subsequent connecting flights that same day through Boston, Atlanta and Orlando.
While visiting relatives in Orlando, the patient developed a fever, chills and a slight cough before being hospitalized Thursday at Dr. P. Phillips Hospital. Hospital staff isolated the patient and forwarded diagnostic tests to state officials and the CDC in Atlanta. The CDC confirmed the MERS virus Sunday night, director Tom Frieden said.
"The patient is in good condition and is improving," said Antonio Crespo, an infectious disease specialist at Dr. P. Phillips Hospital. "We are taking every precaution but believe the risk of transmission from this patient is very low, since his symptoms were mild, and he was not coughing when he arrived at the hospital."
Since March, the number of MERS cases worldwide has increased sharply for unknown reasons, Dr. Schuchat said. Since there's no vaccine or specific antiviral treatment for MERS, the CDC advises the public to protect against respiratory infections by washing hands often and avoiding close contact with sick people. The public also should disinfect frequently touched surfaces and avoid touching their eyes, nose and mouth with unwashed hands.