The role of the traveler in emerging infections and magnitude of travel

Abstract

Travel and trade have grown immensely. Travelers interact with people and microbes during their journeys, and can introduce infectious agents to new areas and populations. Studying illnesses in travelers is a source of knowledge into diseases of resource-poor regions and the control of these diseases. Travel-associated illnesses also serve to detect emerging infections.

Fig. 1

International tourist arrivals by region (millions) with forecast. (Data from WTO Tourism Highlights 2007 and World Tourism Barometer 2008;6(1). Available at http://www.world-tourism.org/facts/menu.html.)

Fig. 2

Measles outbreaks in the United States from January 1 through April 25, 2008. (From CDC. Measles—United States, January 1–April 25, 2008. MMWR Morb Mortal Wkly Rep 2008;57(18):494–8. http://www.cdc.gov/mmwr/PDF/wk/mm5718.pdf; with permission.)

Fig. 3

Wild poliovirus (WPV) cases in 2005 and importation routes during 2002–2005 worldwide. (From CDC. Resurgence of wild poliovirus type 1 transmission and consequences of importation—21 countries, 2002–2005. Morbidity Mortality Weekly Report 2006;55(6):145–50; with permission.)

Fig. 4

Crested Hawk-Eagles confiscated at Brussels International Airport in the hand luggage of a Thai passenger. The birds were wrapped in a cotton cloth, with the heads free, and each of them inserted in a wicker tube ∼60 cm in length, with one end open. (Courtesy of Paul Meuleneire, custom investigations officer, antidrug group. From Van Borm S, Thomas I, Hanquey G, et al. Highly pathogenic H5N1 influenza virus in smuggled Thai eagles, Belgium. Emerg Infect Dis 2005;11(5):702–5. Available from http://www.cdc.gov/ncidod/EID/vol11no05/05-0211.htm.)