FIGURE D-1 The life cycle of the public health response to a new infection.

but more often the threat is recognized as clusters and then communities develop disease.

Collections of body fluids or tissue specimens are needed to identify the pathogen. Diagnostic devices are often an important element in an effective public health response to break the cycle of spread and prevent the emergence of new cases. The World Health Organization estimated that there were 8,096 cases with 774 deaths in 2002 and 2003 (Anderson et al., 2004; WHO, 2004). But by 2006 this SARS pandemic threat had been completely contained.

Parallel to the scientific and public health life cycle is the in vitro diagnostic product life cycle (see Figure D-2). As the clinical specimens from infected patients become available, the search for a pathogen begins. As infectious candidates are identified, analytes, the active ingredients of in vitro diagnostics, are created to develop investigational diagnostic devices. In 2003 SARS-infected clinical specimens were scarce, but with the pathogen identified “spiked” samples could be developed to refine diagnostic methods. Investigational diagnostics for emerging infections are initially tested against available specimens from sporadic cases and epidemiologic studies. As the test develops it may be prospectively studied to evaluate new cases and make decisions about clinical treatment or quarantine. Patient research