ABSTRACT
Introduction Despite remarkable advances in microbial research during the twentieth century, infectious diseases still remain among the leading causes of morbidity and mortality worldwide. More than three dozen new high-impact infectious diseases have been identified since the 1970s. The list includes Legionnaires’ disease, SARS, HIV/AIDS, Lyme disease, hepatitis C, new forms of cholera, crypto sporidium, Ebola, toxic shock syndrome and E. coli 0157:H7, among many others. With this in mind, emerging infectious diseases may serve as a paradigm for handling the public threat of bioterrorism. Figure 1.1 shows the global distribution of some of these agents. With this in mind, it is important to look at emerging pathogens in the context of global biosecurity. We need to understand why these pathogens are emerging, how they will impact us, and what we can do to intervene in that process. We need to understand how naturally occurring agents differ from intentionally introduced, man-made or genetically engineered ones in their spread and ability
to sustain their contagiousness. With vastly different infrastructures and resources, we also need to understand how differently – for better or worse – the third world would handle a pandemic. The global devastation of pandemics of smallpox and plague in the Middle Ages as well as HIV/AIDS and influenza in more recent times has influenced every aspect of life, including life expectancy, economics, health-care delivery, employment, and freedom of movement. Plague in the Middle Ages introduced us to the term “quarantine” when ships, for fear of spreading plague, were unable to unload their cargo and crew for 40 days. Destructive bioagents can linger (e.g., smallpox) or appear, disappear, and reappear without warning (e.g., plague or influenza). Will a biological threat agent like non-contagious anthrax cause more or less harm than contagious agents like pneumonic plague, smallpox, or a hemorrhagic fever virus? Understanding these diseases will help us better prepare for them, avoid them or, at a minimum, diminish their impact. Figure 1.2 shows how the epidemic curve of cases over time could be affected with an efficient response mechanism.
