LOS ANGELES (CBSLA.com) — Travelers at Los Angeles International Airport (LAX) and over a dozen other airports nationwide were being warned Wednesday of the emerging threat of the Middle East Respiratory Syndrome Coronavirus (MERS).

Posters at airport checkpoints in Los Angeles, Las Vegas, San Diego and 16 other U.S. airports have gone up urging passengers to take precautions to avoid the respiratory infection, which originated in the Middle East and has killed an estimated 145 people worldwide.

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There is currently no treatment for the SARS-like MERS, which kills about one in three people who contract it, according to the Centers for Disease Control (CDC).

Health officials are trying to track down around 100 people who may have overlapped with an infected patient at two hospitals in Orlando, Fla., according to CBS News.

Two health care workers at Dr. P. Phillips Hospital who were exposed to the MERS virus by a 44-year-old infected patient both tested negative Wednesday after showing worrisome flu-like symptoms, CBS News reported. Both patients were healthcare workers who live in Saudi Arabia and had been traveling to the U.S., officials said.

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The World Health Organization has reported 571 confirmed cases of MERS, including 171 deaths, in 18 countries.

The virus first emerged about two years ago in the Middle East, according to CDC officials. While cases in the United States have been rare and the World Health Organization said the spread of the disease does not constitute a global health emergency, officials want travelers to the Arabian Peninsula to be aware of MERS symptoms that could be mistaken for the flu.

The CDC recommends all travelers to Saudi Arabia, Qatar, Oman, Jordan, Kuwait and the United Arab Emirates monitor their health closely for 14 days after travel and immediately call a doctor if they experience any MERS symptoms, including fever, cough and shortness of breath.

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