Press Release WHO/96 17 December 1998 WHO GUIDELINES ADDRESS RISK OF TUBERCULOSIS TRANSMISSION DURING AIR TRAVEL The World Health Organization (WHO) today issued guidelines, Tuberculosis and Air Travel: Guidelines for Prevention and Control, to reduce transmission of the disease to the world's 1.4 billion air passengers. WHO stresses that while the risk is low, TB transmission during air travel has been documented. Airlines, passengers, physicians and health authorities need to know the risk and take proper measures to minimize risk of infection and prevent break-down to active TB when infection does occur. "We want to make air travel safer, reduce the risk of TB transmission and increase passengers' confidence that they are adequately protected from risk of infection when they travel," said Dr Mario Raviglione of WHO's Communicable Disease Operational and Epidemiological Research unit. "We are confident that these guidelines will be a substantial aide in achieving that goal." The guidelines have been welcomed by the airline industry. According to Dr Claus Curdt-Christiansen of the International Civil Aviation Organization (ICAO), TB is "one of the most vexing aeromedical problems of modern air transportation". "Within the next decade we can expect more than two billion passengers per year in scheduled air traffic alone," he said. "Long-haul flights combined with the confined space of a passenger cabin and the close proximity to co-passengers from the entire world may facilitate the spread of contagious diseases. In-flight exposure to infectious tuberculosis in co-passengers has become a realistic airline possibility owing to the high prevalence of tuberculosis in some regions of the world. It is to be hoped that WHO's guidelines will be studied by all doctors related to the airline industry and its regulatory agencies and that the recommendations given will be implemented without delay by health authorities and airline companies world-wide." The guidelines were produced in collaboration with international TB experts, civil aviation authorities and airline company representatives. They recommend tracing and informing passengers and crew members who were on a commercial flight with an infectious person, if the flight, including ground delays (during which passengers remain on board the aircraft with little or no ventilation), lasts more than eight hours. This is to be done if less than three months have elapsed between the flight and notification of the case to the health authorities. The guidelines were prompted by increasing reports of TB outbreaks on airlines. Between 1992 and 1996, in studies involving seven patients with active TB and 2600 passengers and crew with whom they had contact, the US Centers for Disease Control and Prevention (CDC) found only a few cases of TB transmission. But because airlines have not always had the proper mechanisms in place to follow up passengers, CDC was not able to reach all passengers on the flights where transmission occurred. There may, consequently, be many additional unreported cases. Once case are notified by the health authorities, airline companies should inform passengers and crew of possible exposure and encourage them to establish whether infection might have occurred and whether preventive therapy is needed, the guidelines say. Incomplete airline records (either because no passenger details have been recorded or those recorded are incorrect) currently make this difficult. WHO says it is essential that airlines maintain as comprehensive and reliable records as possible. In addition, maximum efficiency air filters should be installed and properly maintained on all aircraft and ground delays kept to a minimum. Anyone with infectious TB should postpone travel until they become non-infectious. Boarding can and should be denied to persons known to have infectious TB. The Aerospace Medical Association and the Airline Medical Directors Association also support the recommendations. WHO consists of 191 Member States. Its world headquarters are in Geneva, Switzerland, and it has six Regional Offices: in Harare, Zimbabwe (for Africa), Washington, USA (for the Americas), Copenhagen, Denmark (for Europe), Alexandria, Egypt (for the Eastern Mediterranean), New Delhi, India (for Southeast Asia) and Manila, the Philippines (the Western Pacific). _______________  For further information, journalists can contact Gregory Hartl, Health Communications and Public Relations, WHO, Geneva. Telephone (41 22) 791 4458. Fax (41 22) 791 4858. Email: hartlg@who.ch ; Dr Claus Curdt-Christiansen, ICAO, Canada. Telephone (1 514) 954 6326. Fax (1 514) 954 6077. Email: cchristiansen@icao.int ; Dr Dr Claude Thibeault, Aerospace Medical Association, Air Transport Medicine Committee and Airline Medical Directors Association. Telephone (1 514) 422 7204. Fax (1 514) 422 7995. Email: cthibeault@aircanada.ca ; Dr Brinio Van Zanten, International Airline Medical Advisory Committee Occupational Health, KLM, the Netherlands. Telephone (31) 20 649 1407. Fax (31) 20 648 8174. Email: bvvzanten.arbo@klm.nl . All WHO Press Releases, Fact Sheets and Features as well as other information on this subject can be obtained on Internet on the WHO home page http://www.who.ch/