Soldiers at risk of contracting infectious disease—either from the natural environment or from bioweapons—need diagnostics that are rugged, rapid, and easy to use, according to speaker Mark Wolcott of the Diagnostic Systems Division at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID). In their contribution to this chapter, Wolcott and co-authors discuss the rationale, design, and development of rapid diagnostic assays for infectious diseases. They offer brief, comparative descriptions of a variety of platform technologies that in the future may be combined to produce comprehensive, integrated diagnostic systems—perhaps in the guise of miniaturized “labs on chips” that process samples, perform assays, and automatically report their results. “As technologies mature and new technologies are developed, rapid infectious disease diagnostics will become available and practical,” the authors predict.
Rapid diagnostic tools are also improving infectious disease surveillance in animals. Workshop presenter Alex Ardans, who directs the California Animal Health and Food Safety Laboratory System, described the development of polymerase chain reaction-based (PCR-based) assays to screen for diseases that have caused devastating outbreaks in livestock, such as exotic Newcastle disease (END) in poultry and foot-and-mouth disease (FMD) in cattle. California also developed a highly efficient tuberculosis testing program after the disease was detected in several of the state’s large dairies.
Based on such experiences, Ardans argued that the state’s laboratory system plays its most crucial role when recognizing and responding to unusual disease events. For example, following a recent END outbreak among fighting cocks, whose handlers worked in and spread the disease to commercial poultry operations, the laboratory optimized an existing real-time PCR assay for END that was used to perform more than 85,000 tests (Crossley, 2005). Such emergencies present unique opportunities to improve disease diagnosis, Ardans said, although not necessarily with the latest technology. He noted that laboratory researchers, in pursuit of the source of E. coli O157:H7 following a recent outbreak in spinach, discovered that a gauze swab used to sample irrigation waters for contaminants performed better than newer concentration devices.
Although Koch’s postulates remain diagnostic standards, adapting them to a vastly expanded understanding of disease states has become increasingly problematic, observed presenter Ian Lipkin and co-author Thomas Briese of Columbia University’s Jerome L. and Dawn Greene Infectious Disease Laboratory. Their paper discusses contemporary problems in proving causality, and illustrative case studies that reveal how these challenges are shaping pathogen surveillance and discovery. The authors also provide a taxonomy and comparative guide to proven