The role of the traveler in emerging infections and magnitude of travel.Med Clin North Am. 2008 Nov; 92(6):1409-32, xi.MC
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.