Global changes related to travelers' health.

While many potential threats posed by emerging infections continue to make headlines in the 21st century, limited attention is often paid to well demonstrated and defined infectious disease risks. As eloquently noted recently in TIME Magazine , humanity tends to worry about possibilities, while paying less attention to probabilities.1 This analogy helps to explain the travel‐related concerns regarding H5N1 avian influenza that, to date, has not been acquired by a single traveler in any of the 12 countries that have reported human cases.2 At the same time, many travelers undertake journeys without interventions for infections that routinely cause illnesses and sometimes death. In spite of the periodic undulating concerns regarding avian influenza, we must keep in mind that according to the World Health Organization definition, the world has remained in a static phase 3 influenza “pandemic alert” for 3 full years now.3 Highlighted exotic infections, while often associated with increased concern, have rarely been observed in travelers. For example, similar to most previous outbreaks of Marburg fever, there was no traveler among the 252 cases with 227 deaths reported from Angola in 2005.4 In contrast, the severe acute respiratory syndrome (SARS) epidemic, now faded from travel medicine discussion, has been very relevant in the context of international travel and health. During the 2003 episode, 8,096 cases with 774 deaths were recorded and 142 were imported.5 Transmission occurred in hotels6 and during flights.7 The five cases imported to Canada resulted in 251 cases with an almost paralyzing impact on travel to a major metropolitan center, Toronto. The experience clearly illustrates that some global connections, in this case what apparently happened in restaurants and on markets in Southeastern China, has the potential to become very relevant to all of us. But SARS is now history, … Corresponding Author: Robert Steffen, MD, Institute of Social and Preventive Medicine, University of Zurich, Hirschengraben 84, CH‐8001 Zurich, Switzerland. E‐mail: travclin{at}ifspm.unizh.ch