Updated

Cabin crews and passengers flying overseas have been put on the alert by the Centers for Disease Control and Prevention (CDC), which has posted warnings in 22 U.S. airports about the dangers of the MERS virus.

Though there are no official recommendations to change travel plans just yet, the postings notify travelers about MERS – or Middle East respiratory syndrome coronavirus – and what they can do to avoid infection.

The risk of disease for airplane passengers is extremely low, but the CDC says international travelers should educate themselves on the signs and symptoms of MERS, as well as the regions most affected by the spread of the disease.

“The bottom line is being very cautious, particularly if you’re going to the Arabian Peninsula and have any reason to work in a health care center,” Dr. Marty Cetron, director of global migration and quarantine at the CDC, told FoxNews.com. “That’s really the epicenter of the epidemic.”

According to the World Health Organization, 571 MERS cases have been reported worldwide – 171 of which have proved fatal.  The majority of the cases have occurred in health care settings in Saudi Arabia. While the disease is also commonly found in camels, experts are unsure of whether these animals are responsible for spreading the disease to humans.

MERS symptoms include fever and signs of lower respiratory illness, such as coughing and shortness of breath.  The CDC advises that people who develop these symptoms within 14 days of traveling from countries in and around the Arabian Peninsula should seek testing for the virus.

Recently, the United States confirmed the illness in two health care workers who had just returned from Saudi Arabia and had traveled on multiple airplanes. The first patient has fully recovered and has since been released from the hospital, while the second patient is currently hospitalized and doing well.

In light of these cases, the CDC has contacted approximately 500 airline passengers who may have come in contact with the patients during travel, but so far, none has reported any illness. Cetron noted that health officials believe MERS is not easily transmitted from person to person, but he admitted that ultimately very little is known about how this disease spreads.

“We’re still learning about the transmission characteristics of the coronavirus, but we don’t have all that information yet, which is why we do these types of investigations.  The operating theory and hypothesis is through [human-to-human] contact, but how people are getting it from animals, we don’t understand that yet.”

So far, major transatlantic airlines such as United and American Airlines have not indicated that they will be making any major changes to help prevent the spread of infection.  However, a spokesperson for U.S. Customs and Border Protection (CBP) said the agency has been working with the CDC to develop procedures for identifying travelers with MERS and ways to handle them in a manner that minimizes risk to the public.

“When a traveler or alien is identified with a possible communicable disease or identified from information that is received from the CDC, CBP personnel will take the appropriate safety measures by donning personal protective equipment (PPE), to include gloves and surgical masks, which are readily available for use in the course of their duties,” Jaime Ruiz, a spokesperson for CBP, told FoxNews.com in an email.

But there are also various steps that passengers can take to ensure they stay healthy while flying.

“Wash your hands regularly, avoid sick people and avoid environments that are high risk,” Cetron said.  “Know the signs and symptoms, and if you return from the Arabian Peninsula and you get sick, be sure to call your doctor; say that ‘I was just in Saudi Arabia, where can I be tested for MERS?’”

For more information on MERS travel advisories, visit the CDC's Traveler's Health site.