Denver, was the lack of a surveillance system that could be sustained and available to continuously communicate information to the central command system (Hoffman and Norton, 2000).
Several epidemics of the recent past have illustrated the need for enhanced, more timely reporting of infectious diseases. The 1976 Legionnaires’ Disease outbreak in Pennsylvania is an example of a point-source outbreak of an unknown agent with rapid transmission and high mortality associated with the dispersal of exposed persons (Fraser et al., 1977)—an outbreak that today would certainly require evaluation as a potential bioterrorist attack. Yet surveillance and outbreak data related to this investigation were so unwieldy that they had to be evaluated using mainframe computers (Martin and Bean, 1995). The 1993 hantavirus outbreak in the southwestern United States (CDC, 1993) and the West Nile virus encephalitis outbreak in New York City (CDC, 1999) illustrate the importance of prompt reporting by clinicians in triggered public health investigations. The availability of timely, flexible surveillance systems could have aided in characterizing and determining the scope of the outbreaks after their initial reporting.
CDC notes several recent successes in strengthening surveillance efforts and in implementing new surveillance strategies, and has initiated the Epidemiology and Laboratory Capacity program to provide health departments with laboratory and technical capacity in dealing with emerging infections (CDC, 1998). Seven states have initiated emerging infections programs (EIPs) to conduct population-based surveillance and special research on emerging and re-emerging diseases. Creation of the Foodborne Diseases Active Surveillance Network (FoodNet) within EIPs has provided a model program for outbreak detection within EIPs. Provider-based networks have been established to collect information from nontraditional public health venues (CDC, 1998; Binder et al., 1999). Examples include infectious diseases surveillance in 11 academic emergency rooms (EMERGEncy ID NET) (Talan et al., 1998) a network of enhanced communication among 500 infectious disease practitioners via the Internet (the Infectious Diseases Society of America Emergency Infections Network [IDSA EIN]), and a group of 22 linked travel medicine clinics in the United States and abroad to monitor disease among returning travelers (GeoSentinel) (CDC, 1998). With the exception of the unexplained death and severe illness project within selected EIP sites (discussed below), all of these enhanced or innovative systems rely on the reporting of specific clinically and/or laboratory-confirmed diagnosed cases. None of these systems are based on the reporting of clinical syndromes or groups of clinical signs and symptoms.
Although the need for innovative surveillance techniques had been identified prior to September 11, the U.S. outbreak of anthrax following the intentional delivery of B. anthracis spores through the mail in fall 2001,