The airline industry, which lost billions of dollars after the 2003 outbreak of the SARS virus, is monitoring the burgeoning bird flu threat but plans to wait before instituting any special precautions to guard against the spread of the disease.
"The issue of infectious disease is something that we maintain a healthy vigilance about, and we have pretty close relationships with the [Centers for Disease Control and Prevention] and local health departments about what's out there and what we need to worry about," said Dr. Gary Kohn, United Airlines' corporate medical director.
And the CDC, which typically alerts airlines when extraordinary measures are necessary, has not recommended special precautions at this point.
"We deal with potentially infectious diseases all the time," Kohn said. "We certainly had that before SARS. We have a concern, and we don't want to bring people on board an airplane that might be harmful to other people or themselves."
For airlines, efforts to ensure public confidence in onboard safety are crucial. The SARS outbreak resulted in millions of dollars in lost revenue. For a period, travel to Asia was down more than a third from forsaken vacations and canceled business trips because of customer fears and CDC warnings to avoid unnecessary travel to some regions .
"SARS did a number on everybody, but people don't know about bird flu," said airline analyst Michael Boyd. "That will change if a lot of people start dropping dead someplace quickly."
A virulent strain of avian influenza, discovered in Hong Kong in 1997, has spread to other parts of Asia. While primarily found in chickens and ducks, in rare instances it has infected humans.
The strain, known as influenza A (H3N1), is blamed for at least 60 deaths.
Concerns that bird flu could spread around the world prompted an international flu conference in Washington last week. Health and Human Services Secretary Michael O. Leavitt told attendees that the world is "obviously unprepared or inadequately prepared for the potential of a pandemic."
President Bush met with drugmakers last week, urging them to boost development and production of flu vaccine.
In February, the CDC issued guidelines and recommendations to flight crews about bird flu. It reminded them that the captain of an airliner headed for the United States is required to report suspected cases of the illness to federal health officials before arrival.
The agency recommends that a passenger suspected of carrying the disease be separated as much as possible from other passengers and be given a surgical mask to reduce the spread of germs.
The airline industry's ability to deal with infectious diseases is limited, John Meenan, executive vice president of the Air Transport Association, a trade group for the major carriers, told a congressional aviation subcommittee in April.
"Efficient and affordable air transportation has helped to create a highly mobile international society, which facilitates the exchange of ideas, goods and, unfortunately, viruses," he said.
"The rapid spread of severe acute respiratory syndrome [SARS] underscored that fact," he said.
In the post-SARS environment, the airline industry is better able to track passengers who could have been exposed to an infectious disease on a flight.
The CDC has developed a passenger-locator-card system for airlines. International passengers provide information, making it possible for the CDC to contact and follow up with them in the event of an outbreak.
During the SARS outbreak, flight crews from some airlines donned surgical masks and gloves in hopes of avoiding airborne disease.
That never happened with United's crews, although they were warned about what to watch for, Kohn said. It never reached a point where the airline felt it was necessary for the crew to wear protective clothing, he said.
"If you're screening the passengers, there should be no need to protect yourself," he said. "And if you feel strongly enough about protecting yourself, you probably are out to protect everybody."
If bird flu is determined to be a threat, visible steps will be taken, Kohn said. "Like with SARS, certain things will happen."
The CDC and each country's health agency will require certain procedures, including taking the temperature of some patients before allowing them to board.
Efforts are made to take such steps without scaring or disrupting other passengers, but the airline has to ensure the safety of everyone's health, Kohn said.
"Everybody was understanding that we were erring on the side of caution," he said. "If someone started coughing on the airplane, we gave them a mask and tried to isolate them as much as possible. If avian flu becomes an epidemic, I imagine we'd do that again."
Mark Skertic writes for the Chicago Tribune.