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The ABC Transporter Protein OppA Provides Protection against Experimental Yersinia pestis Infection.
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Tanabe M, Atkins HS, Harland DN, Elvin SJ, Stagg AJ, Mirza O, Titball RW, Byrne B, Brown KA
The identification of Yersinia pestis as a potential bioterrorism agent and the emergence of antibiotic-resistant strains have highlighted the need for improved vaccines and treatments for plague. The aim of this study was to evaluate the potential for ATP-binding cassette (ABC) transporter proteins to be exploited as novel vaccines against plague. Western blotting of ABC transporter proteins using sera from rabbits immunized with killed whole Y. pestis cells or human convalescent-phase sera identified four immunologically reactive proteins: OppA, PstS, YrbD, and PiuA. Mice immunized with these proteins developed antibody to the immunogen. When the immunized mice were challenged with Y. pestis, the OppA-immunized mice showed an increased time to death compared to other groups, and protection appeared to correlate with the level of immunoglobulin G antibody to OppA.
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Basis for the Failure of Francisella tularensis Lipopolysaccharide To Prime Human Polymorphonuclear Leukocytes.
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Barker JH, Weiss J, Apicella MA, Nauseef WM
Francisella tularensis is the intracellular gram-negative coccobacillus that causes tularemia, and its virulence and infectiousness make it a potential agent of bioterrorism. Previous studies using mononuclear leukocytes have shown that the lipopolysaccharide (LPS) of F. tularensis is neither a typical proinflammatory endotoxin nor an endotoxin antagonist. This inertness suggests that F. tularensis LPS does not bind host LPS-sensing molecules such as LPS-binding protein (LBP). Using priming of the polymorphonuclear leukocyte (PMN) oxidase as a measure of endotoxicity, we found that F. tularensis live vaccine strain LPS did not behave like either a classic endotoxin or an endotoxin antagonist in human PMNs, even when the concentration of LBP was limiting. Furthermore, F. tularensis LPS did not compete with a radiolabeled lipooligosaccharide from Neisseria meningitidis for binding to LBP or to the closely related PMN granule protein, bactericidal/permeability-increasing protein. Our results suggest that the inertness of F. tularensis LPS and the resistance of F. tularensis to oxygen-independent PMN killing may result from the inability of F. tularensis LPS to be recognized by these important LPS-sensing molecules of the innate immune system.
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Identifying and quantifying genotypes in polyclonal infections due to single species.
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Colborn JM, Koita OA, Cissé O, Bagayoko MW, Guthrie EJ, Krogstad DJ
Simultaneous infection with multiple pathogens of the same species occurs with HIV, hepatitis C, Epstein-Barr virus, dengue, tuberculosis, and malaria. However, available methods do not distinguish among or quantify pathogen genotypes in individual patients; they also cannot test for novel insertions and deletions in genetically modified organisms. The strategy reported here accomplishes these goals with real-time polymerase chain reaction (PCR) and capillary electrophoresis. Real-time PCR with allotype-specific primers defines the allotypes (strains) present and the intensity of infection (copy number). Capillary electrophoresis defines the number of genotypes within each allotype and the intensity of infection by genotype. This strategy can be used to study the epidemiology of emerging infectious diseases with simultaneous infection by multiple genotypes, as demonstrated here with malaria. It also permits testing for insertions or deletions in genetically modified organisms that may be used for bioterrorism.
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Rickettsia prowazekii and real-time polymerase chain reaction.
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Svraka S, Rolain JM, Bechah Y, Gatabazi J, Raoult D
Rickettsia prowazekii is the causative agent of epidemic typhus and a potential bioterrorism agent. Sensitive and specific rapid assays are needed to complement existing methods of detecting this organism. We developed a real-time quantitative polymerase chain reaction assay by using a species-specific probe targeting the gltA gene. This assay, which was rapid, specific for R. prowazekii only, and sensitive (cutoff detection of 1 to 5 copies per sample), detected and directly identified R. prowazekii in blood of 12 experimentally infected mice sampled at day 3 and 6 postinfection or in naturally or experimentally infected lice. Because our assay is highly standardized and easily adaptable, it could improve epidemic typhus surveillance in public health programs, especially for countries with underdiagnosed or unrecognized human cases.
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Are we preparing health services administration students to respond to bioterrorism and mass casualty management?
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Houser SH, Houser HW
Bioterrorism/natural disaster events add significant specialized demands and disrupt normal operation of the health system, often for an indefinite period of time. Health administration leaders should be educationally prepared for and informed about these potential events, but few receive this knowledge via their academic preparation in health administration. This study examined the existence of coverage of bioterrorism topics in health administration curricula and characteristics of bioterrorism coverage in current health administration programs through a self-completed survey among AUPHA graduate and undergraduate program members. Of the total survey respondents, only 32% of programs have current coverage of bioterrorism. The main reasons for nothavingbioterrorism coverage were not having enough resources; not having enough time to develop course/materials; and not thinking it is necessary to add these courses/materials. To prepare better and to inform future health administrators regarding major disruptive circumstances, advocacy and documentation are important to develop and implement bioterrorism awareness. Possibly, suggested minimum curricular requirements, content, and mechanisms for inclusion can be developed in the near future. Health administration educators should address the new reality and demonstrate that their graduates can function and lead in crises and situations disruptive to normal commerce.
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Francisella tularensis: Taxonomy, Genetics, and Immunopathogenesis of a Potential Agent of Biowarfare.
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McLendon MK, Apicella MA, Allen LA
Tularemia is a zoonosis of humans caused by infection with the facultative intracellular bacterium Francisella tularensis. Interest in F. tularensis has increased markedly in the past few years because of its potential use as an agent of bioterrorism. Five subspecies of this organism are found in the Northern hemisphere, but only F. tularensis subsp. tularensis and subsp. holarctica cause disease in humans. This review summarizes what is known about the pathogenesis of tularemia with a focus on bacterial surface components such as lipopolysaccharide and capsule as well as information obtained from the F. tularensis subsp. tularensis SCHU S4 genome. In particular, the mechanisms of action of recently identified virulence factors are discussed in the context of bacterial replication in macrophages and manipulation of the host inflammatory response. Throughout this report shared and unique features of F. tularensis subsp. tularensis, subsp. holarctica, and subsp. novicida are discussed. Expected online publication date for the Annual Review of Microbiology Volume 60 is September 8, 2006. Please see http://www.annualreviews.org/catalog/pub_dates.asp for revised estimates.
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Animals as sentinels of bioterrorism agents.
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Rabinowitz P
We conducted a systematic review of the scientific literature from 1966 to 2005 to determine whether animals could provide early warning of a bioterrorism attack, serve as markers for ongoing exposure risk, and amplify or propagate a bioterrorism outbreak. We found evidence that, for certain bioterrorism agents, pets, wildlife, or livestock could provide early warning and that for other agents, humans would likely manifest symptoms before illness could be detected in animals. After an acute attack, active surveillance of wild or domestic animal populations could help identify many ongoing exposure risks. If certain bioterrorism agents found their way into animal populations, they could spread widely through animal-to-animal transmission and prove difficult to control. The public health infrastructure must look beyond passive surveillance of acute animal disease events to build capacity for active surveillance and intervention efforts to detect and control ongoing outbreaks of disease in domestic and wild animal populations.
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Review of syndromic surveillance: implications for waterborne disease detection.
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Berger M, Shiau R, Weintraub JM
Syndromic surveillance is the gathering of data for public health purposes before laboratory or clinically confirmed information is available. Interest in syndromic surveillance has increased because of concerns about bioterrorism. In addition to bioterrorism detection, syndromic surveillance may be suited to detecting waterborne disease outbreaks. Theoretical benefits of syndromic surveillance include potential timeliness, increased response capacity, ability to establish baseline disease burdens, and ability to delineate the geographical reach of an outbreak. This review summarises the evidence gathered from retrospective, prospective, and simulation studies to assess the efficacy of syndromic surveillance for waterborne disease detection. There is little evidence that syndromic surveillance mitigates the effects of disease outbreaks through earlier detection and response. Syndromic surveillance should not be implemented at the expense of traditional disease surveillance, and should not be relied upon as a principal outbreak detection tool. The utility of syndromic surveillance is dependent on alarm thresholds that can be evaluated in practice. Syndromic data sources such as over the counter drug sales for detection of waterborne outbreaks should be further evaluated.
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Patient experience with, and use of, an electronic monitoring system to assess vaccination responses.
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Olmsted SS, Grabenstein JD, Jain AK, Lurie N
Abstract Objective To evaluate the user experience and acceptability of an electronic patient monitoring system. Setting and participants 822 Military and civilian personnel at a health clinic at a major US military headquarters used an Internet and telephone-based electronic monitoring system to report vaccination-site responses and symptoms after receiving the smallpox vaccination. Focus groups of vaccinees were conducted to help develop a survey about the experience that was distributed to 379 vaccinees (96% completion rate). Results Users of the electronic monitoring system reported that it was fast and easy to use and reported they would use a system like this again and recommend an electronic monitoring system to a friend or relative. Most users (84%) were comfortable with a physician tracking their vaccine reaction using their electronic reports, but only half (51%) were comfortable with eliminating the post-vaccination follow-up visit with their health-care provider based on their electronic reports. Conclusions This electronic monitoring system was well received by vaccinees and allowed health-care providers to track the status of vaccinees. However, vaccinees were not comfortable replacing a physician visit with electronic monitoring, at least for the smallpox vaccination. A monitoring system like this may be useful in public health settings, such as mass vaccination or prophylaxis during a bioterrorism event, a pandemic influenza outbreak, or another public health emergency.
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Short-course postexposure antibiotic prophylaxis combined with vaccination protects against experimental inhalational anthrax.
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Vietri NJ, Purcell BK, Lawler JV, Leffel EK, Rico P, Gamble CS, Twenhafel NA, Ivins BE, Heine HS, Sheeler R, Wright ME, Friedlander AM
Prevention of inhalational anthrax after Bacillus anthracis spore exposure requires a prolonged course of antibiotic prophylaxis. In response to the 2001 anthrax attack in the United States, approximately 10,000 people were offered 60 days of antibiotic prophylaxis to prevent inhalational anthrax, but adherence to this regimen was poor. We sought to determine whether a short course of antibiotic prophylaxis after exposure could protect non-human primates from a high-dose spore challenge if vaccination was combined with antibiotics. Two groups of 10 rhesus macaques were exposed to approximately 1,600 LD50 of spores by aerosol. Both groups were given ciprofloxacin by orogastric tube twice daily for 14 days, beginning 1-2 h after exposure. One group also received three doses of the licensed human anthrax vaccine (anthrax vaccine adsorbed) after exposure. In the ciprofloxacin-only group, four of nine monkeys (44%) survived the challenge. In contrast, all 10 monkeys that received 14 days of antibiotic plus anthrax vaccine adsorbed survived (P = 0.011). Thus postexposure vaccination enhanced the protection afforded by 14 days of antibiotic prophylaxis alone and completely protected animals against inhalational anthrax. These data provide evidence that postexposure vaccination can shorten the duration of antibiotic prophylaxis required to protect against inhalational anthrax and may impact public health management of a bioterrorism event.
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Follow-up on diagnostic proficiency of laboratories equipped to perform orthopoxvirus detection and quantification by PCR: the second international external quality assurance study.
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Niedrig M, Meyer H, Panning M, Drosten C
Two years after the first external quality assurance study on bioterrorism-relevant viruses, we have conducted a follow-up study on orthopoxvirus detection by PCR. Thirty-three laboratories (27 European, 4 Austral-Asian, and 2 American) participated. Samples contained 0 to 40,000,000 DNA copies of lyophilized monkeypox, cowpox, and vaccinia virus per ml. Laboratories achieved a >80% detection chance above 56,234 copies per ml. Global sensitivity was not significantly improved over that of the first study. Twenty-seven and 9 participants, respectively, were able to genotype and quantify virus. Four of 27 genotyping results were incorrect. Quantification accuracy was significantly better for vaccinia virus than for the other viruses. False-positive results occurred in 22 (11.8%) of all 186 tests on negative samples, but 18 of these were contributed by only five laboratories. Fifty-five percent of laboratories could appropriately detect PCR inhibition. The use of either real-time PCR or commercial diagnostic kits had significant positive influence on laboratory performance.
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Genotyping of Bacillus anthracis strains based on automated capillary 25-loci Multiple Locus Variable-Number Tandem Repeats Analysis.
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Lista F, Faggioni G, Valjevac S, Ciammaruconi A, Vaissaire J, le Doujet C, Gorge O, De Santis R, Carattoli A, Ciervo A, Fasanella A, Orsini F, D'Amelio R, Pourcel C, Cassone A, Vergnaud G
ABSTRACT: BACKGROUND: The genome of Bacillus anthracis, the etiological agent of anthrax, is highly monomorphic which makes differentiation between strains difficult. A Multiple Locus Variable-number tandem repeats (VNTR) Analysis (MLVA) assay based on 20 markers was previously described. It has considerable discrimination power, reproducibility, and low cost, especially since the markers proposed can be typed by agarose-gel electrophoresis. However in an emergency situation, faster genotyping and access to representative databases is necessary. RESULTS: Genotyping of B. anthracis reference strains and isolates from France and Italy was done using a 25 loci MLVA assay combining 21 previously described loci and 4 new ones. DNA was amplified in 4 multiplex PCR reactions and the length of the resulting 25 amplicons was estimated by automated capillary electrophoresis. The results were reproducible and the data were consistent with other gel based methods once differences in mobility patterns were taken into account. Some alleles previously unresolved by agarose gel electrophoresis could be resolved by capillary electrophoresis, thus further increasing the assay resolution. One particular locus, Bams30, is the result of a recombination between a 27 bp tandem repeat and a 9 bp tandem repeat. The analysis of the array illustrates the evolution process of tandem repeats. CONCLUSIONS: In a crisis situation of suspected bioterrorism, standardization, speed and accuracy, together with the availability of reference typing data are important issues, as illustrated by the 2001 anthrax letters event. In this report we describe an upgrade of the previously published MLVA method for genotyping of B. anthracis and apply the method to the typing of French and Italian B. anthracis strain collections. The increased number of markers studied compared to reports using only 8 loci greatly improves the discrimination power of the technique. An Italian strain belonging to the B branch was described, and two new branches, D and E, are proposed. Owing to the upgrading achieved here, precise genotyping can now be produced either by automated capillary electrophoresis, or by the more accessible but slower and for some markers slightly less accurate agarose gel methodology.
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Salmonella-based plague vaccines for bioterrorism.
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Calhoun LN, Kwon YM
Yersinia pestis, the causative agent of plague, is an emerging threat as a means of bioterrorism. Accordingly, the Working Group on Civilian Biodefense, as well as the Centers for Disease Control and Prevention, has specified Y. pestis as a prime candidate for use in bioterrorism. As the threat of bioterrorism increases, so does the need for an effective vaccine against this potential agent. Experts agree that a stable, non-invasive vaccine would be necessary for the rapid large-scale immunization of a population following a bioterrorism attack. Thus far, live Salmonella-based oral vaccines show the most potential for this purpose. When delivered via a mucosal route, Salmonella-based plague vaccines show the ability to protect against the deadly pneumonic form of plague. Also, mass production, distribution, and administration are easier and less costly for attenuated Salmonella-based plague vaccines than for plague vaccines consisting of purified proteins. Most attenuated Salmonella-based plague vaccines have utilized a plasmid-based expression system to deliver plague antigen(s) to the mucosa. However, these systems are frequently associated with plasmid instability, an increased metabolic burden upon the vaccine strain, and highly undesirable antibiotic resistance genes. The future of Salmonella-based plague vaccines seems to lie in the use of chromosomally encoded plague antigens and the use of in vivo inducible promoters to drive their expression. This method of vaccine development has been proven to greatly increase the retention of foreign genes, and also eliminates the need for antibiotic resistance genes within Salmonella-based vaccines.
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Toll-Like Receptor 2 Is Required for Inflammatory Responses to Francisella tularensis LVS.
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Katz J, Zhang P, Martin M, Vogel SN, Michalek SM
Francisella tularensis, a gram-negative bacterium, is the etiologic agent of tularemia and has recently been classified as a category A bioterrorism agent. Infections with F. tularensis result in an inflammatory response that plays an important role in the pathogenesis of the disease; however, the cellular mechanisms mediating this response have not been completely elucidated. In the present study, we determined the role of Toll-like receptors (TLRs) in mediating inflammatory responses to F. tularensis LVS, and the role of NF-kappaB in regulating these responses. Stimulation of bone marrow-derived dendritic cells from C57BL/6 wild-type (wt) and TLR4(-/-) but not TLR2(-/-) mice, with live F. tularensis LVS elicited a dose-dependent increase in the production of tumor necrosis factor alpha. F. tularensis LVS also induced in a dose-dependent manner an up-regulation in the expression of the costimulatory molecules CD80 and CD86 and of CD40 and the major histocompatibility complex class II molecules on dendritic cells from wt and TLR4(-/-) but not TLR2(-/-) mice. TLR6, not TLR1, was shown to be involved in mediating the inflammatory response to F. tularensis LVS, indicating that the functional heterodimer is TLR2/TLR6. Stimulation of dendritic cells with F. tularensis resulted in the activation of NF-kappaB, which resulted in a differential effect on the production of pro- and anti-inflammatory cytokines. Taken together, our results demonstrate the role of TLR2/TLR6 in the host's inflammatory response to F. tularensis LVS in vitro and the regulatory function of NF-kappaB in modulating the inflammatory response.
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Purdue University-Banfield National Companion Animal Surveillance Program for emerging and zoonotic diseases.
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Glickman LT, Moore GE, Glickman NW, Caldanaro RJ, Aucoin D, Lewis HB
A National Companion Animal Surveillance Program (NCASP) was established at Purdue University to monitor clinical syndromes and diseases using the electronic medical records of >80,000 companion animals visiting >500 Banfield hospitals weekly in 44 states. With funding from the Centers for Disease Control and Prevention, NCASP was initially developed for syndromic surveillance of Category A agents of bioterrorism. Surveillance was expanded through inclusion of electronic reports from Antech Diagnostics, a nationwide network of integrated veterinary diagnostic laboratories serving >18,000 private veterinary practices. NCASP characterizes and displays temporal and spatial patterns of diseases in dogs, cats, and other companion animals. It detects unusual clusters of potential emerging/zoonotic infections and monitors flea and tick activity. Data is processed and analyzed using SAS and ESRI software products. The NCASP can be used by veterinarians to enhance their practice of evidence-based medicine by providing information needed to individualize vaccine protocols for animals in specific geographic areas.
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Evaluation of a model training program for respiratory-protection preparedness at local health departments.
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Alfano-Sobsey E, Kennedy B, Beck F, Combs B, Kady W, Ramsey S, Stockweather A, Service W
Respiratory-protection programs have had limited application in local health departments and have mostly focused on protecting employees against exposure to tuberculosis (TB). The need to provide the public health workforce with effective respiratory protection has, however, been underscored by recent concerns about emerging infectious diseases, bioterrorism attacks, drug-resistant microbes, and environmental exposures to microbial allergens (as in recent hurricane flood waters). Furthermore, OSHA has revoked the TB standard traditionally followed by local health departments, replacing it with a more stringent regulation. The additional OSHA requirements may place increased burdens on health departments with limited resources and time. For these reasons, the North Carolina Office of Public Health Preparedness and Response and industrial hygienists of the Public Health Regional Surveillance Teams have developed a training program to facilitate implementation of respiratory protection programs at local health departments. To date, more than 1,400 North Carolina health department employees have been properly fit-tested for respirator use and have received training in all aspects of respiratory protection. This article gives an overview of the development and evaluation of the program. The training approach presented here can serve as a model that other health departments and organizations can use in implementing similar respiratory-protection programs.
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PulseNet USA: a five-year update.
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Gerner-Smidt P, Hise K, Kincaid J, Hunter S, Rolando S, Hyytiä-Trees E, Ribot EM, Swaminathan B,
PulseNet USA is the molecular surveillance network for foodborne infections in the United States. Since its inception in 1996, it has been instrumental in detection, investigation and control of numerous outbreaks caused by Shiga toxin-producing Escherichia coli O157:[H7] (STEC O157), Salmonella enterica, Listeria monocytogenes, Shigella spp., and Campylobacter. This paper describes the current status of the network, including the methodologies used and its future possibilities. The currently preferred subtyping method in the network is pulsed-field gel electrophoresis (PFGE), a proven highly discriminatory molecular subtyping method. New simpler sequencebased subtyping methods are under development and validation to complement and eventually replace PFGE. PulseNet is essentially a cluster detection network, but the data in the system will now also be used in attribution analyses of sporadic infections. The PulseNet platform will also be used as a primary tool in preparedness and response to acts of food bioterrorism.
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Early detection and surveillance for biopreparedness and emerging infectious diseases.
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Veenema TG, Toke J
Biological weapons and emerging infectious diseases pose a significant risk to public health. A timely response is needed to effectively treat and contain a potential infectious disease outbreak. Detection and surveillance of biological agents needs to be sensitive and specific to allow providers to quickly and accurately identify the disease process and begin the necessary response procedures. This article addresses the importance of early detection and surveillance of both intentional and unintentional biological events. Challenges of bioterrorism and the nursing role in response are discussed. Epidemiological considerations, such as route of transmission and personal protective equipment, are presented. An overview of the major surveillance systems, including advances in computer-based technology, is provided to help health care providers become aware of current surveillance systems and clinical decision support tools designed to help diminish the impact of biological threats.
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Alleged B. anthracis exposure claims in a workers' compensation setting.
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Jewell G, Dunning K, Lockey JE
OBJECTIVES: Workers' compensation insurance in some states may not provide coverage for medical evaluation costs of workplace exposures related to potential bioterrorism acts if there is no diagnosed illness or disease. Personal insurance also may not provide coverage for these exposures occurring at the workplace. Governmental entities, insurers, and employers need to consider how to address such situations and the associated costs. The objective of this study was to examine characteristics of workers and total costs associated with workers' compensation claims alleging potential exposure to the bioterrorism organism B. anthracis. METHODS: We examined 192 claims referred for review to the Ohio Bureau of Workers' Compensation (OBWC) from October 10, 2001, through December 20, 2004. RESULTS: Although some cases came from out-of-state areas where B. anthracis exposure was known to exist, no Ohio claim was associated with true B. anthracis exposure or B. anthracis-related illness. Of the 155 eligible claims, 126 included medical costs averaging dollar 219 and ranging from dollar 24 to dollar 3,126. There was no difference in mean cost for government and non-government employees (p = 0.202 Wilcoxon). CONCLUSIONS: The number of claims and associated medical costs for evaluation and treatment of potential workplace exposure to B. anthracis were relatively small. These results can be attributed to several factors, including no documented B. anthracis exposures and disease in Ohio and prompt transmission of recommended diagnostic and prophylactic treatment protocols to physicians. How employers, insurers, and jurisdictions address payment for evaluation and treatment of potential or documented exposures resulting from a potential terrorism-related event should be addressed proactively.
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Detection of norovirus capsid protein in authentic standards and in stool extracts by matrix-assisted laser desorption ionization and nanospray mass spectrometry.
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Colquhoun DR, Schwab KJ, Cole RN, Halden RU
Mass spectrometry (MS) represents a rapid technique for the identification of microbial monocultures, and its adaptation to the detection of pathogens in real-world samples is a public health and homeland security priority. Norovirus, a leading cause of gastroenteritis in the world, is difficult to monitor because it cannot be cultured outside the human body. The detection of norovirus capsid protein was explored using three common MS-based methods: scanning of intact proteins, peptide mass fingerprinting, and peptide sequencing. Detection of intact target protein was limited by poor selectivity and sensitivity. Detection of up to 16 target peptides by peptide mass fingerprinting allowed for the reproducible and confident (P < 0.05) detection of the 56-kDa norovirus capsid protein in the range of 0.1 x 10(-12) to 50 x 10(-12) mol in authentic standards of recombinant norovirus virus-like particles (VLPs). To explore assay performance in complex matrixes, a non-gel-based, rapid method (2 to 3 h) for virus extraction from human stool was evaluated (72% +/- 12% recovery), and additional analyses were performed on norovirus-free stool extracts fortified with VLPs. Whereas peptide mass fingerprinting was rendered impractical by sample interferences, peptide sequencing using nanospray tandem MS facilitated unambiguous identification of > or =250 fmol of capsid protein in stool extracts. This is the first report on MS-based detection of norovirus, accomplished by using structurally identical, noninfective VLPs at clinically relevant concentrations. It represents an important milestone in the development of assays for surveillance of this category B bioterrorism agent.
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