A “controversial” study, released on Sunday, “suggests international rules that bar potentially infectious tuberculosis patients from flying are too stringent and airline passengers are really at little risk from catching TB from a fellow traveler,” the Associated Press/Washington Post reports. The paper is being published in the March edition of Lancet Infectious Diseases (Stobbe, 2/21).

Current WHO recommendations, which were established in 2006 and 2008, “urge health watchdogs to trace and screen passengers who have sat for longer than eight hours in rows adjacent to someone who has tested positive for pulmonary tuberculosis. In addition, an individual with TB should be barred from all commercial air travel until clearing two tests to show he or she is no longer infectious,” writes Agence France-Presse (2/21).

However, the paper concluded that health authorities worldwide “go too far in advising testing of passengers and crew on long flights when an infected flier is discovered,” the AP/Washington Post writes. For the study, Ibrahim Abubakar of the University of East Anglia chaired a European scientific panel that examined TB and air travel. They reviewed 13 studies of 4,300 passengers from six countries. “He concluded that only two studies offered convincing evidence of an infected passenger spreading the disease to others. He counted only 10 infections diagnosed in thousands of passengers who flew with infected travelers,” according to the news service.

According to Abubakar, people who have standard TB and who have been taking drugs for at least two weeks should be allowed to fly on commerical airlines (2/21). He said, “Although an airline cabin is a closed confined space, the cumulative duration of exposure is relative[ly] short compared with households or … other modes of transport where individuals might travel on the same route daily,” he said, AFP reports. He also noted that people who have weakened immune systems have a higher risk of contracting TB, but most people who travel on planes are relatively healthy. “Resources might be better spent addressing other priorities of tuberculosis control and helping all achieve Millennium Development Goals related to tuberculosis,“ according to the paper (2/21).

Abubakar did acknowledge that the “‘consequences are greater’ if a fellow passenger is infected with drug-resistant TB,” according to the AP/Washington Post. Some experts disagree with the paper’s conclusions. CDC Director Thomas Frieden said, “It’s always better to be safe than sorry.” Richard Chaisson, a TB expert at John Hopkins University who sits on the editorial advisory board of Lancet Infectious Diseases, “did not agree with the study’s findings and called them unconvincing. ‘I don’t think there’s a problem’ with World Health Organization or U.S. guidelines” (2/21).