The committee finds that mass spectrometry has the potential to identify biological agents based on a biofingerprint matching method and has the potential to do so with limited reagent consumption. Therefore, the committee recommends that the use of laboratory mass spectrometry be investigated to better understand the performance of biofingerprinting in complex mixtures of naturally occurring microorganisms and other background contaminants. This should be done with parallel development of improved sample preparation methods.
The committee finds that the biological smoke alarm concept offers intriguing potential for rapid detection. This concept uses networked, low-cost, semiselective detectors distributed throughout the rooms in a building. Therefore, the committee recommends that research be conducted to develop and characterize the performance of low-cost arrays of semiselective sensors that can be used as a biological smoke alarm for triggering low-regret response measures.
The committee finds that ribosomal RNA assays might be capable of biothreat agent identification in one to several minutes. This approach, with a major development effort, could avoid the time-consuming amplification cycles of many nucleic acid sequencing assays. Therefore, the committee recommends that the potential and the limitations of rRNA detection for rapid identification of pathogens be explored.
The committee finds that function-based sensors are one of the few promising candidates for detecting unknown hazardous agents—that is, agents that had not been anticipated. Their response time is inherently tied to the time it takes an agent to have a physiological effect on sentinel organisms or tissues. For certain chemical agents and toxins, this effect can be very rapid, but for bacteria and viruses, it can take much longer. These longer response times for bacteria and viruses make it unlikely that function-based sensors will play a significant role in detect-to-warn applications for these agents, but they could nevertheless play a valuable detect-to-treat role in the overall biodetection architecture. Therefore, the committee recommends that studies be conducted to better understand the role of function-based sensors in overall biodetection architectures and to provide goals to focus research and development activities on those areas for which function-based sensors have the highest leverage.
Detection systems that could provide rapid warning for a significant portion of the threat space could be deployed by 2010 to high-value buildings and probably even to military bases. The development and deployment of these systems can significantly reduce the number of casualties associated with a biological attack. Typical requirements are for detection of a broad spectrum of agents in a time approaching 1 minute (including sample collection and preparation) with a very low false alarm rate (about one false alarm per million sampled, corresponding to approximately one false alarm per year). The most promising approach for attaining this uses a combination of advanced detectors: for example, a nonspecific detector capable of detecting any and all biological agents and suitable for defense against medium to large attacks; a rapid, structure-based identifier capable of identifying 10 to 20 of the leading threat agents and suitable for discriminating a low-level attack from the natural background; and an autonomous PCR capability for rapid confirmation of an attack.
The independent use of three different detection techniques results in a very low false alarm rate and a high level of robustness against potential countermeasures. Critical crosscutting needs include rapid and autonomous sample preparation and better characterization of ambient bioaerosol backgrounds and sources, as well as ways to reduce these backgrounds in current and future buildings.
Finally, it should be noted that preventive and passive defenses (including measures such as improved security and threat assessment, as well as improved filtering and balancing of HVAC systems) play a significant role in reducing exposures and in raising the minimum attack level needed to produce significant casualties, thereby making it easier to detect biological agents and to initiate protective responses.