Cost-effectiveness comparison of response strategies to a large-scale anthrax attack on the chicago metropolitan area: impact of timing and surge capacity

United States' regulatory approved pharmacotherapies for nuclear reactor explosions and anthrax-associated bioterrorism

INTRODUCTION

Nuclear reactor incidents and bioterrorism outbreaks are concerning public health disasters. Little is known about US Food and Drug Administration (FDA)-approved agents that can mitigate consequences of these events. We review FDA data supporting regulatory approvals of these agents.

AREAS COVERED

We reviewed pharmaceutical products approved to treat Hematopoietic Acute Radiation Syndrome (H-ARS) and to treat or prevent pulmonary infections following Bacillus anthracis (anthrax) exposure. Four drugs were approved for H-ARS: granulocyte-colony stimulating factor (G-CSF), granulocyte/macrophage colony stimulating factor, pegylated G-CSF, and romiplostim. For bioterrorism-associated anthrax, the FDA approved five antibiotics (doxycycline, penicillin-G, levofloxacin, moxifloxacin, and ciprofloxacin), two monoclonal antibodies (obiltoxaximab and raxibacumab), one polyclonal antitoxin (Anthrax Immune Globulin Intravenous) and two vaccines (Anthrax Vaccine Adsorbed and Anthrax Vaccine Adsorbed with an adjuvant). A national stockpile system ensures that communities have ready access to these agents. Our literature search was based on data included in drugs@FDA (2001-2023).

EXPERT OPINION

Two potential mass public health disasters are aerosolized anthrax dissemination and radiological incidents. Five agents authorized for anthrax emergencies only have FDA approval for this indication, five antibiotics have FDA approvals as antibiotics for common infections and for bacillus anthrax, and four agents have regulatory approvals for supportive care for cancer and for radiological incidents.

Developing Public Health Emergency Response Leaders in Incident Management: A Scoping Review of Educational Interventions

During emergency responses, public health leaders frequently serve in incident management roles that differ from their routine job functions. Leaders' familiarity with incident management principles and functions can influence response outcomes. Therefore, training and exercises in incident management are often required for public health leaders. To describe existing methods of incident management training and exercises in the literature, we queried 6 English language databases and found 786 relevant articles. Five themes emerged: (1) experiential learning as an established approach to foster engaging and interactive learning environments and optimize training design; (2) technology-aided decision support tools are increasingly common for crisis decision-making; (3) integration of leadership training in the education continuum is needed for developing public health response leaders; (4) equal emphasis on competency and character is needed for developing capable and adaptable leaders; and (5) consistent evaluation methodologies and metrics are needed to assess the effectiveness of educational interventions.These findings offer important strategic and practical considerations for improving the design and delivery of educational interventions to develop public health emergency response leaders. This review and ongoing real-world events could facilitate further exploration of current practices, emerging trends, and challenges for continuous improvements in developing public health emergency response leaders.

Estimation of Time Period for Effective Human Inhalational Anthrax Treatment Including Antitoxin Therapy

Introduction:

Infrequent natural human inhalational anthrax cases coupled with high bioterrorism risk have brought about use of animal models to serve as the basis for approval of novel treatments. For inhalational anthrax, protective antigen (PA) drives much of the mortality, and raxibacumab, an anti-PA monoclonal antibody, has been approved for therapeutic use using the Animal Rule. Given the paucity of human inhalational anthrax clinical data including PA kinetics, the post-exposure period for effective treatment of human disease remains unknown. The objective of this investigation was to extrapolate animal PA kinetics to a conceptual human model to estimate the post-exposure period for effective treatment of human inhalational anthrax.

Methods:

Human PA kinetic parameters were extrapolated from reported rabbit and monkey data. PA profiles were simulated with and without antibiotic induced PA clearance to represent antibiotic-sensitive and -resistant infections, respectively. Antitoxin levels equimolar to or greater than concurrent PA levels were considered protective.

Results:

For antibiotic sensitive infections, treatment with antibiotics alone ≤4 days after spore exposure prevents toxemia. Administration of raxibacumab together with antibiotics protects ≥ 80% of subjects for 3 additional days (7 days post exposure). In the setting of antibiotic resistance, raxibacumab would be protective for at least 6 days post exposure.

Conclusions:

Although the animal model of disease does not reflect the potential impact of supportive care (e.g. fluid resuscitation received by critically ill patients) on PA kinetics and raxibacumab PK, the simulations suggest that administration of antitoxin in combination with antibiotics should provide a longer postexposure window for effective treatment than for antibiotics alone. In addition, raxibacumab administration soon after exposure to an antibiotic resistant strain should provide effective treatment.

Developments in Surge Research Priorities: A Systematic Review of the Literature Following the Academic Emergency Medicine Consensus Conference, 2007-2015

OBJECTIVES

In 2006, Academic Emergency Medicine (AEM) published a special issue summarizing the proceedings of the AEM consensus conference on the "Science of Surge." One major goal of the conference was to establish research priorities in the field of "disasters" surge. For this review, we wished to determine the progress toward the conference's identified research priorities: 1) defining criteria and methods for allocation of scarce resources, 2) identifying effective triage protocols, 3) determining decision-makers and means to evaluate response efficacy, 4) developing communication and information sharing strategies, and 5) identifying methods for evaluating workforce needs.

METHODS

Specific criteria were developed in conjunction with library search experts. PubMed, Embase, Web of Science, Scopus, and the Cochrane Library databases were queried for peer-reviewed articles from 2007 to 2015 addressing scientific advances related to the above five research priorities identified by AEM consensus conference. Abstracts and foreign language articles were excluded. Only articles with quantitative data on predefined outcomes were included; consensus panel recommendations on the above priorities were also included for the purposes of this review. Included study designs were randomized controlled trials, prospective, retrospective, qualitative (consensus panel), observational, cohort, case-control, or controlled before-and-after studies. Quality assessment was performed using a standardized tool for quantitative studies.

RESULTS

Of the 2,484 unique articles identified by the search strategy, 313 articles appeared to be related to disaster surge. Following detailed text review, 50 articles with quantitative data and 11 concept papers (consensus conference recommendations) addressed at least one AEM consensus conference surge research priority. Outcomes included validation of the benchmark of 500 beds/million of population for disaster surge capacity, effectiveness of simulation- and Internet-based tools for forecasting of hospital and regional demand during disasters, effectiveness of reverse triage approaches, development of new disaster surge metrics, validation of mass critical care approaches (altered standards of care), use of telemedicine, and predictions of optimal hospital staffing levels for disaster surge events. Simulation tools appeared to provide some of the highest quality research.

CONCLUSION

Disaster simulation studies have arguably revolutionized the study of disaster surge in the intervening years since the 2006 AEM Science of Surge conference, helping to validate some previously known disaster surge benchmarks and to generate new surge metrics. Use of reverse triage approaches and altered standards of care, as well as Internet-based tools such as Google Flu Trends, have also proven effective. However, there remains significant work to be done toward standardizing research methodologies and outcomes, as well as validating disaster surge metrics.

Risk-Based Decision Making for Reoccupation of Contaminated Areas Following a Wide-Area Anthrax Release

This article presents an analysis of postattack response strategies to mitigate the risks of reoccupying contaminated areas following a release of Bacillus anthracis spores (the bacterium responsible for causing anthrax) in an urban setting. The analysis is based on a hypothetical attack scenario in which individuals are exposed to B. anthracis spores during an initial aerosol release and then placed on prophylactic antibiotics that successfully protect them against the initial aerosol exposure. The risk from reoccupying buildings contaminated with spores due to their reaerosolization and inhalation is then evaluated. The response options considered include: decontamination of the buildings, vaccination of individuals reoccupying the buildings, extended evacuation of individuals from the contaminated buildings, and combinations of these options. The study uses a decision tree to estimate the costs and benefits of alternative response strategies across a range of exposure risks. Results for best estimates of model inputs suggest that the most cost-effective response for high-risk scenarios (individual chance of infection exceeding 11%) consists of evacuation and building decontamination. For infection risks between 4% and 11%, the preferred option is to evacuate for a short period, vaccinate, and then reoccupy once the vaccine has taken effect. For risks between 0.003% and 4%, the preferred option is to vaccinate only. For risks below 0.003%, none of the mitigation actions have positive expected monetary benefits. A sensitivity analysis indicates that for high-infection-likelihood scenarios, vaccination is recommended in the case where decontamination efficacy is less than 99.99%.

Evaluation of direct 16S rDNA sequencing as a metagenomics-based approach to screening bacteria in bottled water

Deliberate or accidental contamination of food, feed, and water supplies poses a threat to human health worldwide. A rapid and sensitive detection technique that could replace the current labor-intensive and time-consuming culture-based methods is highly desirable. In addition to species-specific assays, such as PCR, there is a need for generic methods to screen for unknown pathogenic microorganisms in samples. This work presents a metagenomics-based direct-sequencing approach for detecting unknown microorganisms, using Bacillus cereus (as a model organism for B. anthracis) in bottled water as an example. Total DNA extraction and 16S rDNA gene sequencing were used in combination with principle component analysis and multicurve resolution to study detection level and possibility for identification. Results showed a detection level of 10(5) to 10(6) CFU/L. Using this method, it was possible to separate 2 B. cereus strains by the principal component plot, despite the close sequence resemblance. A linear correlation between the artificial contamination level and the relative amount of the Bacillus artificial contaminant in the metagenome was observed, and a relative amount value above 0.5 confirmed the presence of Bacillus. The analysis also revealed that background flora in the bottled water varied between the different water types that were included in the study. This method has the potential to be adapted to other biological matrices and bacterial pathogens for fast screening of unknown bacterial threats in outbreak situations.

The planning, execution, and evaluation of a mass prophylaxis full-scale exercise in cook county, IL

Increasing threats of bioterrorism and the emergence of novel disease agents, including the recent international outbreaks of H7N9 influenza and MERS-CoV, have stressed the importance and highlighted the need for public health preparedness at local, regional, and national levels. To test plans that were developed for mass prophylaxis scenarios, in April 2013 the Cook Country Department of Public Health (CCDPH) and the Triple Community (TripCom) Medical Reserve Corps (MRC) executed a full-scale mass prophylaxis exercise in response to a simulated anthrax bioterrorism attack. The exercise took place over 2 days and included the TripCom Point-of-Dispensing (POD) Management Team, volunteers from the TripCom MRC, and neighboring public health departments and MRCs. Individuals from the community volunteered as actors during the exercise, while local municipal, police, and fire personnel coordinated their responses to create the most realistic simulation possible. The exercise was designed to test the capacity of TripCom and CCDPH to implement plans for organizing municipal staff and volunteers to efficiently distribute prophylaxis to the community. Based on results from POD clinic flow, accuracy of prophylaxis distribution, and observations from evaluators, the exercise was successful in demonstrating areas that were operationally efficient as well as identifying areas that can be improved on. These include improvements to the just-in-time training for POD staff, the health screening and consent forms handed out to patients, the physical setup of the POD, and the command structure and communication for the management of POD operations. This article demonstrates the need for full-scale exercises and identifies gaps in POD planning that can be integrated into future plans, exercises, and emergency response.