Globalization of human infectious disease

Globalization has facilitated the spread of numerous infectious agents to all corners of the planet. We compiled a global infectious disease database, and showed for the first time that the globalization of human infectious agents depends significantly on the range of hosts used. We show that human infectious agents are broadly and uniformly distributed around the globe, but the magnitude of distribution varies greatly with host requirement, mode of transmission and infectious agent taxonomy. Contagious disease agents are highly globalized, while multi-host, and most significantly, zoonotic infectious agents are much more localized. In addition, the majority of human infectious agents are present on each continent, but human specific and multi-host infectious agents are more broadly distributed than zoonotic infectious agents, which are more locally distributed. Human specific infectious agents exhibit the greatest degree of globalization among continents, followed by multi-host infectious agents, and finally zoonotic infectious agents. A similar pattern emerges at the scale of nations. These findings raise a serious concern for public health and leaves nations with the task of determining the infectious agents that have the greatest potential to establish within their borders.