Travel

Travel changes people and places. The traveler can be the target and sufferer from microbial threats; the traveler can also provide the microbial transport system. Traveling humans alter infectious diseases patterns by introducing pathogenic microbes or resistance, or virulence factors into new populations. The movement of pathogenic microbes through history has been intimately linked to the capacity of humans to travel and to migrate to new locations. Today, humans have the capacity to reach virtually any city in the world within a day or two. Travel to tropical and developing countries are increasing more rapidly than travel to developed countries, and all projections suggest that human travel will continue to increase in the foreseeable future. Infectious diseases influence decisions about travel and trade; and travelers change the epidemiology of infectious diseases. Travel has played an essential role in the movement of HIV/AIDS throughout the world. Rapid international air travel moved the virus that causes SARS to multiple countries within weeks. Travel has been and will continue to be important in the movement of human influenza. Travel consists of sequential shared environments, often with people from diverse regions of the world. It should be considered a loop, and not just an origin and destination. Travel has created extensively interconnected world in terms of microbial threats.