Sorting out the TB threat

6/2/2007

An air passenger traveling with drug-resistant tuberculosis underscores the urgency of better public protection protocol

JUST how dangerous is the health threat from a person infected with tuberculosis traveling on a passenger airliner? Public health officials have surprising differences of opinion on that issue, confusion that must be sorted out to ensure an appropriate level of protection for all air travelers from communicable disease.

Prompting the question is the case of a Georgia man who, knowing he had some form of TB, flew from Atlanta to Paris for his wedding and honeymoon, took four short flights while in Europe, then flew from Prague to Canada before driving back into the United States.

He's now in federally ordered isolation for treatment - the first such quarantine since 1963 - and officials are trying to locate and alert at least 80 people who sat near him on the trans-Atlantic flights.

To make matters confusing, the man blithely ignored the admonition of health officials in Georgia to put off his trip, and he was all the way to Rome before he was notified that test results showed he had the "extensively drug-resistant" (XDR) form of the disease, considered especially dangerous because it does not respond to recognized anti-tuberculosis pharmaceuticals.

Because tuberculosis in any form is spread chiefly by sneezing and coughing, the confines of an airliner cabin with recirculated air would seem to be a perfect environment for infection. But Dr. Martin Cetron, director of the federal Centers for Disease Control and Prevention, said officials believe the patient's "degree of infectiousness is quite low."

The CDC's fact sheet on XDR tuberculosis says that travelers should avoid "high risk settings" such as crowded hospitals, prisons, homeless shelters, "and other settings where susceptible persons come in contact" with TB-infected people. But it adds, "Air travel itself carries a relatively low risk of infection with TB of any kind."

An epidemiologist at Hunter College in New York City, quoted by the New York Times, concurred that the patient in question was unlikely to be infectious and said that CDC had overreacted in isolating the man, imposing "a maximum penalty for a minor medical problem."

Nonetheless, Dr. Richard Wenzel, president of the international society for infectious diseases, decried the patient as "grossly irresponsible," and said no one with active tuberculosis - XDR or not - should be on an airplane.

Indeed, tuberculosis has a long and well-deserved history as a scourge of mankind. In the late 19th century, it killed one-seventh of the populations of the U.S. and Europe before being brought under reasonable control through medical and public health advances.

Even so, TB remains the second-leading killer of adults in the world. Stunningly, some 2 billion people are infected, and 1.6 million die annually. The disease made a resurgence in this country from 1985 to 1992, but the infection rate since has decreased steadily, the CDC says. There were 13,767 reported cases in the U.S. in 2006, but just 49 of the XDR variety from 1993 to 2006.

In view of TB's deadly reputation, and because instances of drug-resistant diseases seem to pop up with greater regularity, sorting out the actual danger to travelers should be a CDC priority.

In addition, the agency needs to clarify its protocol for handling cases like that of the Georgia bridegroom so that the public can be given timely, accurate information.