Passengers on a US Airways flight from Austin to Phoenix were told to get tested for tuberculosis after another traveler was thought to carry the disease. Creative Commons

Passengers on US Airways Flight 2846 were shocked to learn that they might have been exposed to tuberculosis after a traveler was removed from the aircraft for suspected infection with the contagious lung disease. According to WEAR-TV, when the plane traveling from Austin, Texas, landed at Phoenix's Sky Harbor Airport on Saturday, paramedics and police swarmed the aircraft. Emergency personnel then boarded the plane and removed a man who it was later announced may have had tuberculosis, an airborne disease caused by a bacterium.

“As we were taxiing, a stewardess came down the aisle,” Dean Davidson, a passenger on US Airways Flight 2846, told KNXV-TV. “She had a mask and she instructed the gentleman to put a mask on.”

Davidson said a fireman told the passengers that the man had tuberculosis and may have been contagious. The fireman instructed the passengers to see their physicians and to get tested for the disease.

Authorities were alerted to the traveler’s possible tuberculosis infection after the U.S. Centers for Disease Control and Prevention changed his status to “no-fly.” According to The Los Angeles Times, the CDC notified the Transportation Security Administration, which in turn warned the airline, but the plane was already in the air.

“The warning that came from the CDC did not occur until after the flight had departed, so the passenger did not have a red flag in their reservation system or any warning there,” a spokesperson for the airline told reporters, according to KVUE. “Passengers were provided some information about what had occurred. And we are following up the situation with the CDC and monitoring it with them.”

Investigators are still trying to figure out if the man really did have tuberculosis. He is being tested at a hospital. A spokesperson for the CDC said Sunday that it’s still unclear. "And even if a passenger had infectious TB, the duration of the flight was so short that there would likely be no risk of exposure to other passengers,” she said, according to Dallas News.

The spokesperson also said the man was not coughing or sneezing, which would make the risk of transmission extremely low.

This isn’t the first time someone with TB flew while infected. According to CNN, in 2010 a person infected with TB boarded a US Airways flight from Philadelphia to San Francisco even though the person was listed on the CDC’s “Do Not Board” list. The CDC’s list is different from the TSA’s “No Fly” list.

“To request that a person be placed on the public health [do not board] list, state or local public health officials contact the CDC Quarantine Station for their region,” the CDC noted in a statement on its website. “Health-care providers make requests by contacting their state or local public health departments.”

The CDC has a few requirements for adding someone to the “do not board” list. For one, the CDC must first determine that the person has a communicable disease that would pose a “serious public health threat” to other travelers. The CDC must also conclude that the person is unlikely to follow public health recommendations regarding treatment for the disease, and that they “likely will attempt to board a commercial aircraft.”

Once a person is on the CDC’s no-fly list, they cannot be issued a boarding pass.