Most commercial generators are driven by
a. wind.
b. falling water.
c. steam.
d. rain.

The cold war era has passed. The fall of the Berlin Wall in 1989 marked the beginning of the disappearance of old borders and a new global era of unparalleled human movement and interaction. Although the new global arena has created economic opportunities and growth, the benefits have not been equally distributed, and the risks—especially the health risks—of this increasingly interconnected and fast-paced world continue to grow. As people, products, food, and capital travel the world in unprecedented numbers and at historic speeds, so, too, do the myriad of disease-causing microorganisms. The worldwide resurgence of dengue fever, the introduction of West Nile virus into New York City in 1999, the rapid spread of human immunodeficiency virus (HIV) infection in Russia, and the global spread of multidrug-resistant tuberculosis (TB) are but a few examples of the profound effects of globalizing forces on the emergence, distribution, and spread of infectious diseases. No nation is immune to the growing global threat that can be posed by an isolated outbreak of infectious disease in a seemingly remote part of the world. Today, whether carried by an unknowing traveler or an opportunistic vector, human pathogens can rapidly arrive anywhere in the world.

At the same time, the very interdependency and connectedness that create such opportunities for the global spread of pathogens also offer mechanisms for innovative, multinational efforts to address the threat. A growing network of such efforts, combined with the global proliferation of technology and information, continues to strengthen the global public health capacity to prevent and control the spread of emerging and reemerging infectious diseases. One participant in the Workshop on the Impact of Globalization on Infectious Disease Emergence and Control described the situation thus: just as the globalization of infectious diseases is characterized by a transformation of separate entities into a unified epidemiological system, disease control capacity in one part of the globe can readily be deployed to fight diseases in other parts of the world.