Estimating the Location and Spatial Extent of a Covert Anthrax Release

Rapidly identifying the features of a covert release of an agent such as anthrax could help to inform the planning of public health mitigation strategies. Previous studies have sought to estimate the time and size of a bioterror attack based on the symptomatic onset dates of early cases. We extend the scope of these methods by proposing a method for characterizing the time, strength, and also the location of an aerosolized pathogen release. A back-calculation method is developed allowing the characterization of the release based on the data on the first few observed cases of the subsequent outbreak, meteorological data, population densities, and data on population travel patterns. We evaluate this method on small simulated anthrax outbreaks (about 25–35 cases) and show that it could date and localize a release after a few cases have been observed, although misspecifications of the spore dispersion model, or the within-host dynamics model, on which the method relies can bias the estimates. Our method could also provide an estimate of the outbreak's geographical extent and, as a consequence, could help to identify populations at risk and, therefore, requiring prophylactic treatment. Our analysis demonstrates that while estimates based on the first ten or 15 observed cases were more accurate and less sensitive to model misspecifications than those based on five cases, overall mortality is minimized by targeting prophylactic treatment early on the basis of estimates made using data on the first five cases. The method we propose could provide early estimates of the time, strength, and location of an aerosolized anthrax release and the geographical extent of the subsequent outbreak. In addition, estimates of release features could be used to parameterize more detailed models allowing the simulation of control strategies and intervention logistics

Interim Consequence Management Guidance for a Wide-Area Biological Attack

Abstract not provide

Bioterrorism

This book consists of nine chapters, written by international authorities, discussing various aspects of bioterrorism preparedness and response. Five of the chapters are agent-specific and highlight the pathogenesis, prevention and treatment, and the potential of specific organisms (Rickettsia and Yersinia pestis) or toxins (ricin, botulinum neurotoxins, and staphylococcal enterotoxins) to be used for nefarious purposes. Four chapters discuss different aspects of detecting and responding to a bioterrorism attack. These include methods for spatio-temporal disease surveillance, international laboratory response strategies, detection of botulinum neurotoxins in food and other matrices, and the use of physical methods (ie Raman spectroscopy) to detect spores

Retracing Micro-Epidemics of Chagas Disease Using Epicenter Regression

Vector-borne transmission of Chagas disease has become an urban problem in the city of Arequipa, Peru, yet the debilitating symptoms that can occur in the chronic stage of the disease are rarely seen in hospitals in the city. The lack of obvious clinical disease in Arequipa has led to speculation that the local strain of the etiologic agent, Trypanosoma cruzi, has low chronic pathogenicity. The long asymptomatic period of Chagas disease leads us to an alternative hypothesis for the absence of clinical cases in Arequipa: transmission in the city may be so recent that most infected individuals have yet to progress to late stage disease. Here we describe a new method, epicenter regression, that allows us to infer the spatial and temporal history of disease transmission from a snapshot of a population's infection status. We show that in a community of Arequipa, transmission of T. cruzi by the insect vector Triatoma infestans occurred as a series of focal micro-epidemics, the oldest of which began only around 20 years ago. These micro-epidemics infected nearly 5% of the community before transmission of the parasite was disrupted through insecticide application in 2004. Most extant human infections in our study community arose over a brief period of time immediately prior to vector control. According to our findings, the symptoms of chronic Chagas disease are expected to be absent, even if the strain is pathogenic in the chronic phase of disease, given the long asymptomatic period of the disease and short history of intense transmission. Traducción al español disponible en Alternative Language Text S1/A Spanish translation of this article is available in Alternative Language Text S

Retracing Micro-Epidemics of Chagas Disease Using Epicenter Regression

Vector-borne transmission of Chagas disease has become an urban problem in the city of Arequipa, Peru, yet the debilitating symptoms that can occur in the chronic stage of the disease are rarely seen in hospitals in the city. The lack of obvious clinical disease in Arequipa has led to speculation that the local strain of the etiologic agent, Trypanosoma cruzi, has low chronic pathogenicity. The long asymptomatic period of Chagas disease leads us to an alternative hypothesis for the absence of clinical cases in Arequipa: transmission in the city may be so recent that most infected individuals have yet to progress to late stage disease. Here we describe a new method, epicenter regression, that allows us to infer the spatial and temporal history of disease transmission from a snapshot of a population\u27s infection status. We show that in a community of Arequipa, transmission of T. cruzi by the insect vector Triatoma infestans occurred as a series of focal micro-epidemics, the oldest of which began only around 20 years ago. These micro-epidemics infected nearly 5% of the community before transmission of the parasite was disrupted through insecticide application in 2004. Most extant human infections in our study community arose over a brief period of time immediately prior to vector control. According to our findings, the symptoms of chronic Chagas disease are expected to be absent, even if the strain is pathogenic in the chronic phase of disease, given the long asymptomatic period of the disease and short history of intense transmission

Antibody Architecture: Responding to Bioterrorism

Bioterrorism, the use of biological and chemical agents for terrorist purposes, is one of the most potentially significant health and security threats currently facing the United States. Healthcare facilities as isolated entities are alone unable to provide sufficient, adaptable emergency response options during a bioterrorist attack--an unpredictable, low probability, high consequence event. Bioterrorism response must be systemic, distributed, flexible, and responsive for a wide range of event incidents, scenarios and contexts. A significant problem yet to be adequately addressed is the mitigation of the walking well--those who are not sick or injured but have the potential to inundate any designated response setting. Architectural interventions alone are limited in their ability to provide an appropriate response to an act of bioterrorism. An analogy to the human immune system and how it operates in the body to overcome pathogens will be used to articulate a systematic bioterrorism response and a series of architectural interventions for dealing with the walking well. Similar to our immune system, a response network (or system) should be created that operates throughout high risk urban contexts and takes advantage of existing architectural settings in order to deploy as needed and where needed in response to a bioterrorist attack. An antibody response to bioterrorism must be able to adapt to meeting the needs of various scenarios and contexts in which an incident might occur. Drawing on this biological metaphor, any proposed architectural interventions must include latent capabilities while having the ability to be activated in place and scalable in order to accommodate the multiple potential threats and the many variables inherent with bioterrorism. The proposal for an architectural response to bioterrorism is situated in Washington, D.C., identified as the highest potential target city in the United States for acts of bioterrorism. Appropriate latent resources capable of acting as a part of the response network throughout the D.C. urban context will be identified and their potential activation will be explored through two example scenarios, which will be used to illustrate the proposed model for systematic response. The most architecturally significant locations for (activated) small scale interjections will be designed to meet the first response needs of the general population who would be moving about in the city during the detection of an event. These sites and features will allow for differing degrees of self-diagnosis during and following an event as well as provide general day to day and event related public health information. The proposed architectural interjections will be designed to respond to the predicted fear and panic exhibited by the walking well during a bioterrorist attack, and minimize their potential for overwhelming hospitals and other healthcare settings in the target region

First Responder Knowledge and Training Needs for Bioterrorism

Objective: The 2001 anthrax attacks highlighted the need to protect first responders from bioterrorism attacks. While there have been updates to response protocols, the focus of these protocols varies,and first responders may still be unprepared. This study seeks to address the problem of a lack of a specific, universal bioterrorism training program for first responders. The research 1) determines current training practices for bioterrorism incidents, 2) evaluates the effectiveness of current training procedures, 3) investigates differences in training programs based on geography and organization, and 4) assesses attitudes and perceptions of bioterrorism and training. It also identifies areas of weakness and suggests where future training efforts should be focused. Methods: First Responders Knowledge and Training Needs is a descriptive study based on interviews and a survey. The study used a questionnaire containing a combination of qualitative and quantitative questions. Subjects included 70 first responders from the United States who were recruited at a national conference and through personal and professional networking. Subjects’ intuitive assessments of dispersion were contrasted with results of simple dispersion models, the Gaussian puff equation for an outdoor release (Long et al. 2006) and a completely mixed compartment model for an indoor release (Hong et al. 2010). Results: 17.4% of participants did not have any training regarding bioterrorism, while a plurality of participants (29%) had received awareness level training, which is designed for those who require the skills necessary to recognize and report an incident or are likely to witness or investigate an incident. Less than one quarter of participants (24%) had on-line training, and the majority (39%) was trained in-residence at their facility. Less than half of the participants had been trained on how to use on-site testing devices, how to handle an indoor release scenario, or how to handle an outdoor release scenario. Low confidence levels were found regarding the use of on-scene testing devices and responding to outdoor release scenarios. This low confidence responding to an outdoor release where weak evidence was found that participants underestimate downwind risks and overestimate anthrax transfers perpendicular to wind direction during an outdoor release. Regarding personal protective equipment, participants gave varied responses to the level they would choose and the location at which they would dress. Conclusions: A rapid response to a bioterrorism attack is critical for ensuring the safety of American citizens and can save costs associated with medical attention, cleanup, and decontamination efforts (Keim and Kaufmann, 1999 Educating first responders on the proper level and use of personal protective equipment is necessary to ensure they are protected and do not infect their colleagues or family. Utilizing alternative training programs, such as a “train-the-trainer” approach or on-line programs could also increase the number for first responders who have the knowledge and ability to respond to a bioterrorism attack.M.P.H., Public Health -- Drexel University, 201