Globally Mobile Populations and the Spread of Emerging Pathogens

Abstract

Uring the past decade, the global public health commu- nity has been challenged by the emergence and rapid worldwide spread of novel infl uenza strains, severe acute respiratory syndrome, chikungunya virus, drug-resistant tuberculosis, and other conditions and pathogens. Modern transportation and increased tourism, business travel, and immigration contributed to dissemination of these high-im- pact pathogens. The effectiveness of interventions such as airport screening, travel restrictions, and other community mitigation measures remains uncertain. However, human migration has occurred for centuries and will continue, de- spite the threats posed by microbes. Medicine and public health traditionally have focused on the individual pathogens. Today, however, we should look more closely at globally mobile populations that move pathogens across international borders. In addition, we should consider what travelers' behaviors, demographics, or geographic origins tell us about the microbial hitchhik- ers they might bring with them. Travel and migration medicine are unique disciplines because of their dual focus on protecting the health of the individual and protecting the community in which that in- dividual lives, works, or travels. Articles in this issue high- light globally mobile populations and stimulate thought about a recurring theme in travel and migration medicine: better identifi cation and defi nition of at-risk travelers. We need to be able to identify these populations of travelers and characterize them appropriately so we can better iden- tify modifi able risk factors and target interventions to keep travelers safe and healthy during and after their journeys. Globally mobile population is a fairly broad, inten- tionally inclusive term. The fi elds of travel and tropical medicine usually are associated with preparing tourists for international journeys or evaluating such travelers when they return sick. Articles in this issue demonstrate a much broader concern because of the existence of many different types of globally mobile populations. This issue features articles on some of those populations: refugees, immi- grants (legal and not), long-term travelers, pregnant trav- elers, guest workers, soldiers, cruise ship passengers, and imported animals (1-6). These extremely different popu-